Presented by: Ashwin (Microsoft Azure MVP)
APT1 is a Chinese threat group that has been attributed to the 2nd Bureau of the People’s Liberation Army (PLA) General Staff Department’s (GSD) 3rd Department, commonly known by its Military Unit Cover Designator (MUCD) as Unit 61398.
Source:
MITRE ATT&CK® Matrix for Enterprise
Now, let's see the details around the series of events associated with this group in chronological order, and how we can work to mitigate or detect these threats.
APT1 has registered hundreds of domains for use in operations.
Adversaries may purchase domains that can be used during targeting. Domain names are the human readable names used to represent one or more IP addresses. They can be purchased or, in some cases, acquired for free.
Adversaries can use purchased domains for a variety of purposes, including for Phishing, Drive-by Compromise, and Command and Control. Adversaries may choose domains that are similar to legitimate domains, including through use of homoglyphs or use of a different top-level domain (TLD). Typosquatting may be used to aid in delivery of payloads via Drive-by Compromise. Adversaries can also use internationalized domain names (IDNs) to create visually similar lookalike domains for use in operations.
Domain registrars each maintain a publicly viewable database that displays contact information for every registered domain. Private WHOIS services display alternative information, such as their own company data, rather than the owner of the domain. Adversaries may use such private WHOIS services to obscure information about who owns a purchased domain. Adversaries may further interrupt efforts to track their infrastructure by using varied registration information and purchasing domains with different domain registrars.
Pre-compromise
Organizations may intentionally register similar domains to their own to deter adversaries from creating typosquatting domains. Other facets of this technique cannot be easily mitigated with preventive controls since it is based on behaviors performed outside of the scope of enterprise defenses and controls.
Monitoring the following activities in your Organization can help you detect this technique.
Domain Name: Active DNS
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Monitor for queried domain name system (DNS) registry data that may purchase domains that can be used during targeting. Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access and Command and Control.
Domain Name: Domain Registration
Information about domain name assignments and other domain metadata (ex: WHOIS)
Domain registration information is, by design, captured in public registration logs. Consider use of services that may aid in tracking of newly acquired domains, such as WHOIS databases and/or passive DNS. In some cases it may be possible to pivot on known pieces of domain registration information to uncover other infrastructure purchased by the adversary. Consider monitoring for domains created with a similar structure to your own, including under a different TLD. Though various tools and services exist to track, query, and monitor domain name registration information, tracking across multiple DNS infrastructures can require multiple tools/services or more advanced analytics. Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access and Command and Control.
Domain Name: Passive DNS
Logged domain name system (DNS) data highlighting timelines of domain to IP address resolutions (ex: passive DNS)
Monitor for logged domain name system (DNS) data that may purchase domains that can be used during targeting. Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access and Command and Control.
APT1 hijacked FQDNs associated with legitimate websites hosted by hop points.
Adversaries may hijack domains and/or subdomains that can be used during targeting. Domain registration hijacking is the act of changing the registration of a domain name without the permission of the original registrant. Adversaries may gain access to an email account for the person listed as the owner of the domain. The adversary can then claim that they forgot their password in order to make changes to the domain registration. Other possibilities include social engineering a domain registration help desk to gain access to an account or taking advantage of renewal process gaps.
Subdomain hijacking can occur when organizations have DNS entries that point to non-existent or deprovisioned resources. In such cases, an adversary may take control of a subdomain to conduct operations with the benefit of the trust associated with that domain.
Pre-compromise
This technique cannot be easily mitigated with preventive controls since it is based on behaviors performed outside of the scope of enterprise defenses and controls.
Monitoring the following activities in your Organization can help you detect this technique.
Domain Name: Active DNS
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Monitor for queried domain name system (DNS) registry data that may hijack domains and/or subdomains that can be used during targeting. Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on related stages of the adversary lifecycle, such as during Command and Control.
Domain Name: Domain Registration
Information about domain name assignments and other domain metadata (ex: WHOIS)
Consider monitoring for anomalous changes to domain registrant information and/or domain resolution information that may indicate the compromise of a domain. Efforts may need to be tailored to specific domains of interest as benign registration and resolution changes are a common occurrence on the internet.
Domain Name: Passive DNS
Logged domain name system (DNS) data highlighting timelines of domain to IP address resolutions (ex: passive DNS)
Monitor for logged domain name system (DNS) registry data that may hijack domains and/or subdomains that can be used during targeting.Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on related stages of the adversary lifecycle, such as during Command and Control.
APT1 has created email accounts for later use in social engineering, phishing, and when registering domains.
Adversaries may create email accounts that can be used during targeting. Adversaries can use accounts created with email providers to further their operations, such as leveraging them to conduct Phishing for Information or Phishing. Adversaries may also take steps to cultivate a persona around the email account, such as through use of Social Media Accounts, to increase the chance of success of follow-on behaviors. Created email accounts can also be used in the acquisition of infrastructure (ex: Domains).
To decrease the chance of physically tying back operations to themselves, adversaries may make use of disposable email services.
Pre-compromise
This technique cannot be easily mitigated with preventive controls since it is based on behaviors performed outside of the scope of enterprise defenses and controls.
Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access (ex: Phishing).
APT1 used publicly available malware for privilege escalation.
Adversaries may buy, steal, or download malware that can be used during targeting. Malicious software can include payloads, droppers, post-compromise tools, backdoors, packers, and C2 protocols. Adversaries may acquire malware to support their operations, obtaining a means for maintaining control of remote machines, evading defenses, and executing post-compromise behaviors.
In addition to downloading free malware from the internet, adversaries may purchase these capabilities from third-party entities. Third-party entities can include technology companies that specialize in malware development, criminal marketplaces (including Malware-as-a-Service, or MaaS), or from individuals. In addition to purchasing malware, adversaries may steal and repurpose malware from third-party entities (including other adversaries).
Pre-compromise
This technique cannot be easily mitigated with preventive controls since it is based on behaviors performed outside of the scope of enterprise defenses and controls.
Monitoring the following activities in your Organisation can help you detect this technique.
Malware Repository: Malware Content
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Consider analyzing malware for features that may be associated with malware providers, such as compiler used, debugging artifacts, code similarities, or even group identifiers associated with specific MaaS offerings. Malware repositories can also be used to identify additional samples associated with the developers and the adversary utilizing their services. Identifying overlaps in malware use by different adversaries may indicate malware was obtained by the adversary rather than developed by them. In some cases, identifying overlapping characteristics in malware used by different adversaries may point to a shared quartermaster.
Malware Repository: Malware Metadata
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Monitor for contextual data about a malicious payload, such as compilation times, file hashes, as well as watermarks or other identifiable configuration information. Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on post-compromise phases of the adversary lifecycle.
APT1 has used various open-source tools for privilege escalation purposes.
Adversaries may buy, steal, or download software tools that can be used during targeting. Tools can be open or closed source, free or commercial. A tool can be used for malicious purposes by an adversary, but (unlike malware) were not intended to be used for those purposes (ex: PsExec). Tool acquisition can involve the procurement of commercial software licenses, including for red teaming tools such as Cobalt Strike. Commercial software may be obtained through purchase, stealing licenses (or licensed copies of the software), or cracking trial versions.
Adversaries may obtain tools to support their operations, including to support execution of post-compromise behaviors. In addition to freely downloading or purchasing software, adversaries may steal software and/or software licenses from third-party entities (including other adversaries).
Pre-compromise
This technique cannot be easily mitigated with preventive controls since it is based on behaviors performed outside of the scope of enterprise defenses and controls.
Monitoring the following activities in your Organisation can help you detect this technique.
Malware Repository: Malware Metadata
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Monitor for contextual data about a malicious payload, such as compilation times, file hashes, as well as watermarks or other identifiable configuration information. In some cases, malware repositories can also be used to identify features of tool use associated with an adversary, such as watermarks in Cobalt Strike payloads. Much of this activity will take place outside the visibility of the target organization, making detection of this behavior difficult. Detection efforts may be focused on post-compromise phases of the adversary lifecycle.
APT1 has sent spearphishing emails containing malicious attachments.
Adversaries may send spearphishing emails with a malicious attachment in an attempt to gain access to victim systems. Spearphishing attachment is a specific variant of spearphishing. Spearphishing attachment is different from other forms of spearphishing in that it employs the use of malware attached to an email. All forms of spearphishing are electronically delivered social engineering targeted at a specific individual, company, or industry. In this scenario, adversaries attach a file to the spearphishing email and usually rely upon User Execution to gain execution. Spearphishing may also involve social engineering techniques, such as posing as a trusted source.
There are many options for the attachment such as Microsoft Office documents, executables, PDFs, or archived files. Upon opening the attachment (and potentially clicking past protections), the adversary's payload exploits a vulnerability or directly executes on the user's system. The text of the spearphishing email usually tries to give a plausible reason why the file should be opened, and may explain how to bypass system protections in order to do so. The email may also contain instructions on how to decrypt an attachment, such as a zip file password, in order to evade email boundary defenses. Adversaries frequently manipulate file extensions and icons in order to make attached executables appear to be document files, or files exploiting one application appear to be a file for a different one.
Antivirus/Antimalware
Anti-virus can also automatically quarantine suspicious files.
Network Intrusion Prevention
Network intrusion prevention systems and systems designed to scan and remove malicious email attachments can be used to block activity.
Restrict Web-Based Content
Block unknown or unused attachments by default that should not be transmitted over email as a best practice to prevent some vectors, such as .scr, .exe, .pif, .cpl, etc. Some email scanning devices can open and analyze compressed and encrypted formats, such as zip and rar that may be used to conceal malicious attachments.
Software Configuration
Use anti-spoofing and email authentication mechanisms to filter messages based on validity checks of the sender domain (using SPF) and integrity of messages (using DKIM). Enabling these mechanisms within an organization (through policies such as DMARC) may enable recipients (intra-org and cross domain) to perform similar message filtering and validation.
User Training
Users can be trained to identify social engineering techniques and spearphishing emails.
Monitoring the following activities in your Organization can help you detect this technique.
Application Log: Application Log Content
Logging, messaging, and other artifacts provided by third-party services (ex: metrics, errors, and/or alerts from mail/web applications)
Monitor for third-party application logging, messaging, and/or other artifacts that may send spearphishing emails with a malicious attachment in an attempt to gain access to victim systems. Filtering based on DKIM+SPF or header analysis can help detect when the email sender is spoofed. Anti-virus can potentially detect malicious documents and attachments as they're scanned to be stored on the email server or on the user's computer. Monitor for suspicious descendant process spawning from Microsoft Office and other productivity software.
File: File Creation
Initial construction of a new file (ex: Sysmon EID 11)
Monitor for newly constructed files from a spearphishing emails with a malicious attachment in an attempt to gain access to victim systems.
Network Traffic: Network Traffic Content
Logged network traffic data showing both protocol header and body values (ex: PCAP)
Monitor and analyze SSL/TLS traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)). Filtering based on DKIM+SPF or header analysis can help detect when the email sender is spoofed.
Network Traffic: Network Traffic Flow
Summarized network packet data, with metrics, such as protocol headers and volume (ex: Netflow or Zeek http.log)
Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
APT1 has sent spearphishing emails containing hyperlinks to malicious files.
Adversaries may send spearphishing emails with a malicious link in an attempt to gain access to victim systems. Spearphishing with a link is a specific variant of spearphishing. It is different from other forms of spearphishing in that it employs the use of links to download malware contained in email, instead of attaching malicious files to the email itself, to avoid defenses that may inspect email attachments. Spearphishing may also involve social engineering techniques, such as posing as a trusted source.
All forms of spearphishing are electronically delivered social engineering targeted at a specific individual, company, or industry. In this case, the malicious emails contain links. Generally, the links will be accompanied by social engineering text and require the user to actively click or copy and paste a URL into a browser, leveraging User Execution. The visited website may compromise the web browser using an exploit, or the user will be prompted to download applications, documents, zip files, or even executables depending on the pretext for the email in the first place. Adversaries may also include links that are intended to interact directly with an email reader, including embedded images intended to exploit the end system directly or verify the receipt of an email (i.e. web bugs/web beacons).
Adversaries may also utilize links to perform consent phishing, typically with OAuth 2.0 request URLs that when accepted by the user provide permissions/access for malicious applications, allowing adversaries to Steal Application Access Tokens. These stolen access tokens allow the adversary to perform various actions on behalf of the user via API calls.
Audit
Audit applications and their permissions to ensure access to data and resources are limited based upon necessity and principle of least privilege.
Restrict Web-Based Content
Determine if certain websites that can be used for spearphishing are necessary for business operations and consider blocking access if activity cannot be monitored well or if it poses a significant risk.
Software Configuration
Use anti-spoofing and email authentication mechanisms to filter messages based on validity checks of the sender domain (using SPF) and integrity of messages (using DKIM). Enabling these mechanisms within an organization (through policies such as DMARC) may enable recipients (intra-org and cross domain) to perform similar message filtering and validation.
User Account Management
Azure AD Administrators apply limitations upon the ability for users to grant consent to unfamiliar or unverified third-party applications.
User Training
Users can be trained to identify social engineering techniques and spearphishing emails with malicious links which includes phishing for consent with OAuth 2.0
Monitoring the following activities in your Organization can help you detect this technique.
Application Log: Application Log Content
Logging, messaging, and other artifacts provided by third-party services (ex: metrics, errors, and/or alerts from mail/web applications)
Monitor for third-party application logging, messaging, and/or other artifacts that may send spearphishing emails with a malicious link in an attempt to gain access to victim systems. Filtering based on DKIM+SPF or header analysis can help detect when the email sender is spoofed. URL inspection within email (including expanding shortened links) can help detect links leading to known malicious sites. Detonation chambers can be used to detect these links and either automatically go to these sites to determine if they're potentially malicious, or wait and capture the content if a user visits the link.
Network Traffic: Network Traffic Content
Logged network traffic data showing both protocol header and body values (ex: PCAP)
Monitor and analyze SSL/TLS traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure). Consider correlation with process monitoring and command line to detect anomalous processes execution and command line arguments associated to traffic patterns (e.g. monitor anomalies in use of files that do not normally initiate connections for respective protocol(s)).
Network Traffic: Network Traffic Flow
Summarized network packet data, with metrics, such as protocol headers and volume (ex: Netflow or Zeek http.log)
Monitor network data for uncommon data flows. Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious.
APT1 has used the Windows command shell to execute commands, and batch scripting to automate execution.
Adversaries may abuse the Windows command shell for execution. The Windows command shell (cmd) is the primary command prompt on Windows systems. The Windows command prompt can be used to control almost any aspect of a system, with various permission levels required for different subsets of commands. The command prompt can be invoked remotely via Remote Services such as SSH.
Batch files (ex: .bat or .cmd) also provide the shell with a list of sequential commands to run, as well as normal scripting operations such as conditionals and loops. Common uses of batch files include long or repetitive tasks, or the need to run the same set of commands on multiple systems.
Adversaries may leverage cmd to execute various commands and payloads. Common uses include cmd to execute a single command, or abusing cmd interactively with input and output forwarded over a command and control channel.
Execution Prevention
Use application control where appropriate.
Monitoring the following activities in your Organization can help you detect this technique.
Command: Command Execution
Invoking a computer program directive to perform a specific task (ex: Windows EID 4688 of cmd.exe showing command-line parameters, ~/.bash_history, or ~/.zsh_history)
Monitor executed commands and arguments that may abuse the Windows command shell for execution. Usage of the Windows command shell may be common on administrator, developer, or power user systems depending on job function. If scripting is restricted for normal users, then any attempt to enable scripts running on a system would be considered suspicious. If scripts are not commonly used on a system, but enabled, scripts running out of cycle from patching or other administrator functions are suspicious. Scripts should be captured from the file system when possible to determine their actions and intent.
Process: Process Creation
Birth of a new running process (ex: Sysmon EID 1 or Windows EID 4688)
Monitor for newly executed processes that may abuse the Windows command shell for execution.
The file name AcroRD32.exe, a legitimate process name for Adobe's Acrobat Reader, was used by APT1 as a name for malware.
Adversaries may match or approximate the name or location of legitimate files or resources when naming/placing them. This is done for the sake of evading defenses and observation. This may be done by placing an executable in a commonly trusted directory (ex: under System32) or giving it the name of a legitimate, trusted program (ex: svchost.exe). In containerized environments, this may also be done by creating a resource in a namespace that matches the naming convention of a container pod or cluster. Alternatively, a file or container image name given may be a close approximation to legitimate programs/images or something innocuous.
Adversaries may also use the same icon of the file they are trying to mimic.
Code Signing
Require signed binaries and images.
Execution Prevention
Use tools that restrict program execution via application control by attributes other than file name for common operating system utilities that are needed.
Restrict File and Directory Permissions
Use file system access controls to protect folders such as C:\Windows\System32.
Monitoring the following activities in your Organization can help you detect this technique.
File: File Metadata
Contextual data about a file, which may include information such as name, the content (ex: signature, headers, or data/media), user/ower, permissions, etc.
Collect file hashes; file names that do not match their expected hash are suspect. Perform file monitoring; files with known names but in unusual locations are suspect. Likewise, files that are modified outside of an update or patch are suspect.
Image: Image Metadata
Contextual data about a virtual machine image such as name, resource group, state, or type
In containerized environments, use image IDs and layer hashes to compare images instead of relying only on their names. Monitor for the unexpected creation of new resources within your cluster in Kubernetes, especially those created by atypical users.
Process: Process Metadata
Contextual data about a running process, which may include information such as environment variables, image name, user/owner, etc.
Collecting and comparing disk and resource filenames for binaries by looking to see if the InternalName, OriginalFilename, and/or ProductName match what is expected could provide useful leads, but may not always be indicative of malicious activity.
The APT1 group is known to have used pass the hash.
Adversaries may "pass the hash" using stolen password hashes to move laterally within an environment, bypassing normal system access controls. Pass the hash (PtH) is a method of authenticating as a user without having access to the user's cleartext password. This method bypasses standard authentication steps that require a cleartext password, moving directly into the portion of the authentication that uses the password hash.
When performing PtH, valid password hashes for the account being used are captured using a Credential Access technique. Captured hashes are used with PtH to authenticate as that user. Once authenticated, PtH may be used to perform actions on local or remote systems.
Adversaries may also use stolen password hashes to "overpass the hash." Similar to PtH, this involves using a password hash to authenticate as a user but also uses the password hash to create a valid Kerberos ticket. This ticket can then be used to perform Pass the Ticket attacks.
Privileged Account Management
Limit credential overlap across systems to prevent the damage of credential compromise and reduce the adversary's ability to perform Lateral Movement between systems.
Update Software
Apply patch KB2871997 to Windows 7 and higher systems to limit the default access of accounts in the local administrator group.
User Account Control
Enable pass the hash mitigations to apply UAC restrictions to local accounts on network logon. The associated Registry key is located HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\LocalAccountTokenFilterPolicy.
Through GPO: Computer Configuration > [Policies] > Administrative Templates > SCM: Pass the Hash Mitigations: Apply UAC restrictions to local accounts on network logons.[18]
User Account Management
Do not allow a domain user to be in the local administrator group on multiple systems.
Monitoring the following activities in your Organization can help you detect this technique.
Active Directory: Active Directory Credential Request
A user requested active directory credentials, such as a ticket or token (ex: Windows EID 4769)
Monitor requests of new ticket granting ticket or service tickets to a Domain Controller. Windows Security events such as 4768 (A Kerberos authentication ticket (TGT) was requested) and 4769 (A Kerberos service ticket was requested) combined with logon session creation information may be indicative of an overpass the hash attempt.
Logon Session: Logon Session Creation
Initial construction of a new user logon session (ex: Windows EID 4624, /var/log/utmp, or /var/log/wmtp)
Monitor newly created logons and credentials used in events and review for discrepancies. Unusual remote logins that correlate with other suspicious activity (such as writing and executing binaries) may indicate malicious activity.
User Account: User Account Authentication
An attempt by a user to gain access to a network or computing resource, often by providing credentials (ex: Windows EID 4625 or /var/log/auth.log)
Monitor for user authentication attempts. From a classic Pass-The-Hash perspective, this technique uses a hash through the NTLMv1 / NTLMv2 protocol to authenticate against a compromised endpoint. This technique does not touch Kerberos. Therefore, NTLM LogonType 3 authentications that are not associated to a domain login and are not anonymous logins are suspicious. From an Over-Pass-The-Hash perspective, an adversary wants to exchange the hash for a Kerberos authentication ticket (TGT). One way to do this is by creating a sacrificial logon session with dummy credentials (LogonType 9) and then inject the hash into that session which triggers the Kerberos authentication process.
APT1 has been known to use credential dumping using Mimikatz.
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS). After a user logs on, the system generates and stores a variety of credential materials in LSASS process memory. These credential materials can be harvested by an administrative user or SYSTEM and used to conduct Lateral Movement using Use Alternate Authentication Material.
As well as in-memory techniques, the LSASS process memory can be dumped from the target host and analyzed on a local system.
For example, on the target host use procdump:
Locally, mimikatz can be run using:
Built-in Windows tools such as comsvcs.dll can also be used:
Windows Security Support Provider (SSP) DLLs are loaded into LSSAS process at system start. Once loaded into the LSA, SSP DLLs have access to encrypted and plaintext passwords that are stored in Windows, such as any logged-on user's Domain password or smart card PINs. The SSP configuration is stored in two Registry keys: HKLM\SYSTEM\CurrentControlSet\Control\Lsa\Security Packages and HKLM\SYSTEM\CurrentControlSet\Control\Lsa\OSConfig\Security Packages. An adversary may modify these Registry keys to add new SSPs, which will be loaded the next time the system boots, or when the AddSecurityPackage Windows API function is called.
The following SSPs can be used to access credentials:
Behavior Prevention on Endpoint
On Windows 10, enable Attack Surface Reduction (ASR) rules to secure LSASS and prevent credential stealing.
Credential Access Protection
With Windows 10, Microsoft implemented new protections called Credential Guard to protect the LSA secrets that can be used to obtain credentials through forms of credential dumping. It is not configured by default and has hardware and firmware system requirements. It also does not protect against all forms of credential dumping.
Operating System Configuration
Consider disabling or restricting NTLM. Consider disabling WDigest authentication.
Password Policies
Ensure that local administrator accounts have complex, unique passwords across all systems on the network.
Privileged Account Management
Do not put user or admin domain accounts in the local administrator groups across systems unless they are tightly controlled, as this is often equivalent to having a local administrator account with the same password on all systems. Follow best practices for design and administration of an enterprise network to limit privileged account use across administrative tiers.
Privileged Process Integrity
On Windows 8.1 and Windows Server 2012 R2, enable Protected Process Light for LSA.
User Training
Limit credential overlap across accounts and systems by training users and administrators not to use the same password for multiple accounts.
Monitoring the following activities in your Organisation can help you detect this technique.
Command: Command Execution
Invoking a computer program directive to perform a specific task (ex: Windows EID 4688 of cmd.exe showing command-line parameters, ~/.bash_history, or ~/.zsh_history)
Monitor executed commands and arguments that may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS). Remote access tools may contain built-in features or incorporate existing tools like Mimikatz. PowerShell scripts also exist that contain credential dumping functionality, such as PowerSploit's Invoke-Mimikatz module, which may require additional logging features to be configured in the operating system to collect necessary information for analysis.
Process: OS API Execution
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Monitor for API calls that may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
Process: Process Access
Opening of a process by another process, typically to read memory of the target process (ex: Sysmon EID 10)
Monitor for unexpected processes interacting with LSASS.exe. Common credential dumpers such as Mimikatz access LSASS.exe by opening the process, locating the LSA secrets key, and decrypting the sections in memory where credential details are stored. Credential dumpers may also use methods for reflective Process Injection to reduce potential indicators of malicious activity.
Process: Process Creation
Birth of a new running process (ex: Sysmon EID 1 or Windows EID 4688)
Monitor for newly executed processes that may be indicative of credential dumping. On Windows 8.1 and Windows Server 2012 R2, monitor Windows Logs for LSASS.exe creation to verify that LSASS started as a protected process.
APT1 used the commands net start and tasklist to get a listing of the services on the system.
Adversaries may try to gather information about registered local system services. Adversaries may obtain information about services using tools as well as OS utility commands such as sc query, tasklist /svc, systemctl --type=service, and net start.
Adversaries may use the information from System Service Discovery during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.
This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.
Monitoring the following activities in your Organization can help you detect this technique.
Command: Command Execution
Invoking a computer program directive to perform a specific task (ex: Windows EID 4688 of cmd.exe showing command-line parameters, ~/.bash_history, or ~/.zsh_history)
Monitor executed commands and arguments that could be taken to gather system information related to services. Remote access tools with built-in features may interact directly with the Windows API to gather information. Information may also be acquired through Windows system management tools such as Windows Management Instrumentation and PowerShell.
Process: Process Creation
Birth of a new running process (ex: Sysmon EID 1 or Windows EID 4688)
Monitor for newly executed processes with arguments that may try to get information about registered services. System and network discovery techniques normally occur throughout an operation as an adversary learns the environment. Data and events should not be viewed in isolation, but as part of a chain of behavior that could lead to other activities, such as Lateral Movement, based on the information obtained.
APT1 used the ipconfig /all command to gather network configuration information.
Adversaries may look for details about the network configuration and settings, such as IP and/or MAC addresses, of systems they access or through information discovery of remote systems. Several operating system administration utilities exist that can be used to gather this information. Examples include Arp, ipconfig/ifconfig, nbtstat, and route.
Adversaries may also leverage a Network Device CLI on network devices to gather information about configurations and settings, such as IP addresses of configured interfaces and static/dynamic routes.
Adversaries may use the information from System Network Configuration Discovery during automated discovery to shape follow-on behaviors, including determining certain access within the target network and what actions to do next.
This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.
Monitoring the following activities in your Organization can help you detect this technique.
Command: Command Execution
Invoking a computer program directive to perform a specific task (ex: Windows EID 4688 of cmd.exe showing command-line parameters, ~/.bash_history, or ~/.zsh_history)
Monitor executed commands and arguments that may look for details about the network configuration and settings, such as IP and/or MAC addresses, of systems they access or through information discovery of remote systems.
Process: OS API Execution
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Monitor for API calls (such as GetAdaptersInfo() and GetIpNetTable()) that may gather details about the network configuration and settings, such as IP and/or MAC addresses.
Process: Process Creation
Birth of a new running process (ex: Sysmon EID 1 or Windows EID 4688)
Monitor for executed processes (such as ipconfig/ifconfig and arp) with arguments that may look for details about the network configuration and settings, such as IP and/or MAC addresses.
Script: Script Execution
Launching a list of commands through a script file (ex: Windows EID 4104)
Monitor for any attempts to enable scripts running on a system would be considered suspicious. If scripts are not commonly used on a system, but enabled, scripts running out of cycle from patching or other administrator functions are suspicious. Scripts should be captured from the file system when possible to determine their actions and intent.
APT1 used the net use command to get a listing on network connections.
Adversaries may attempt to get a listing of network connections to or from the compromised system they are currently accessing or from remote systems by querying for information over the network.
An adversary who gains access to a system that is part of a cloud-based environment may map out Virtual Private Clouds or Virtual Networks in order to determine what systems and services are connected. The actions performed are likely the same types of discovery techniques depending on the operating system, but the resulting information may include details about the networked cloud environment relevant to the adversary's goals. Cloud providers may have different ways in which their virtual networks operate. Similarly, adversaries who gain access to network devices may also perform similar discovery activities to gather information about connected systems and services.
Utilities and commands that acquire this information include netstat, "net use," and "net session" with Net. In Mac and Linux, netstat and lsof can be used to list current connections. who -a and w can be used to show which users are currently logged in, similar to "net session". Additionally, built-in features native to network devices and Network Device CLI may be used.
This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.
Monitoring the following activities in your Organization can help you detect this technique.
Command: Command Execution
Invoking a computer program directive to perform a specific task (ex: Windows EID 4688 of cmd.exe showing command-line parameters, ~/.bash_history, or ~/.zsh_history)
Monitor executed commands and arguments that may attempt to get a listing of network connections to or from the compromised system they are currently accessing or from remote systems by querying for information over the network. Information may also be acquired through Windows system management tools such as Windows Management Instrumentation and PowerShell.
Process: OS API Execution
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Monitor for API calls that may attempt to get a listing of network connections to or from the compromised system they are currently accessing or from remote systems by querying for information over the network.
Process: Process Creation
Birth of a new running process (ex: Sysmon EID 1 or Windows EID 4688)
Monitor for executed processes that may attempt to get a listing of network connections to or from the compromised system they are currently accessing or from remote systems by querying for information over the network.
APT1 gathered a list of running processes on the system using tasklist /v.
Adversaries may attempt to get information about running processes on a system. Information obtained could be used to gain an understanding of common software/applications running on systems within the network. Adversaries may use the information from Process Discovery during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.
In Windows environments, adversaries could obtain details on running processes using the Tasklist utility via cmd or Get-Process via PowerShell. Information about processes can also be extracted from the output of Native API calls such as CreateToolhelp32Snapshot. In Mac and Linux, this is accomplished with the ps command. Adversaries may also opt to enumerate processes via /proc.
This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.
Monitoring the following activities in your Organization can help you detect this technique.
Command: Command Execution
Invoking a computer program directive to perform a specific task (ex: Windows EID 4688 of cmd.exe showing command-line parameters, ~/.bash_history, or ~/.zsh_history)
Monitor executed commands and arguments for actions that may attempt to get information about running processes on a system.
Process: OS API Execution
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Monitor for API calls may attempt to get information about running processes on a system.
Process: Process Creation
Birth of a new running process (ex: Sysmon EID 1 or Windows EID 4688)
Monitor for newly executed processes that may attempt to get information about running processes on a system.
APT1 used the commands net localgroup,net user, and net group to find accounts on the system.
Adversaries may attempt to get a listing of local system accounts. This information can help adversaries determine which local accounts exist on a system to aid in follow-on behavior.
Commands such as net user and net localgroup of the Net utility and id and groupson macOS and Linux can list local users and groups. On Linux, local users can also be enumerated through the use of the /etc/passwd file. On macOS the dscl . list /Users command can be used to enumerate local accounts.
Operating System Configuration
Prevent administrator accounts from being enumerated when an application is elevating through UAC since it can lead to the disclosure of account names. The Registry key is located at HKLM\ SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\CredUI\EnumerateAdministrators. It can be disabled through GPO: Computer Configuration > [Policies] > Administrative Templates > Windows Components > Credential User Interface: Enumerate administrator accounts on elevation.
Monitoring the following activities in your Organisation can help you detect this technique.
Command: Command Execution
Invoking a computer program directive to perform a specific task (ex: Windows EID 4688 of cmd.exe showing command-line parameters, ~/.bash_history, or ~/.zsh_history)
Monitor for execution of commands and arguments associated with enumeration or information gathering of local accounts and groups such as net user, net account, net localgroup, Get-LocalUser, and dscl.
System and network discovery techniques normally occur throughout an operation as an adversary learns the environment, and also to an extent in normal network operations. Therefore discovery data and events should not be viewed in isolation, but as part of a chain of behavior that could lead to other activities, such as Lateral Movement, based on the information obtained.
File: File Access
Opening a file, which makes the file contents available to the requestor (ex: Windows EID 4663)
Monitor access to file resources that contain local accounts and groups information such as /etc/passwd, /Users directories, and the Windows SAM database.
If access requires high privileges, look for non-admin objects (such as users or processes) attempting to access restricted file resources.
Process: OS API Execution
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Monitor for API calls (such as NetUserEnum()) that may attempt to gather local accounts information such as type of user, privileges and groups.
Process: Process Creation
Birth of a new running process (ex: Sysmon EID 1 or Windows EID 4688)
Monitor for processes that can be used to enumerate user accounts and groups such as net.exe and net1.exe, especially when executed in quick succession. Information may also be acquired through Windows system management tools such as Windows Management Instrumentation and PowerShell.
APT1 listed connected network shares.
Adversaries may look for folders and drives shared on remote systems as a means of identifying sources of information to gather as a precursor for Collection and to identify potential systems of interest for Lateral Movement. Networks often contain shared network drives and folders that enable users to access file directories on various systems across a network. File sharing over a Windows network occurs over the SMB protocol. Net can be used to query a remote system for available shared drives using the net view \\remotesystem command. It can also be used to query shared drives on the local system using net share. For macOS, the sharing -l command lists all shared points used for smb services.
Operating System Configuration
Enable Windows Group Policy "Do Not Allow Anonymous Enumeration of SAM Accounts and Shares" security setting to limit users who can enumerate network shares.
Monitoring the following activities in your Organisation can help you detect this technique.
Command: Command Execution
Invoking a computer program directive to perform a specific task (ex: Windows EID 4688 of cmd.exe showing command-line parameters, ~/.bash_history, or ~/.zsh_history)
Monitor executed commands and arguments that may create and cultivate social media accounts that can be used during targeting.
Process: OS API Execution
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Monitor for API calls that may create and cultivate social media accounts that can be used during targeting.
Process: Process Creation
Birth of a new running process (ex: Sysmon EID 1 or Windows EID 4688)
Monitor for newly executed processes that may create and cultivate social media accounts that can be used during targeting.
The APT1 group is known to have used RDP during operations.
Adversaries may use Valid Accounts to log into a computer using the Remote Desktop Protocol (RDP). The adversary may then perform actions as the logged-on user.
Remote desktop is a common feature in operating systems. It allows a user to log into an interactive session with a system desktop graphical user interface on a remote system. Microsoft refers to its implementation of the Remote Desktop Protocol (RDP) as Remote Desktop Services (RDS).
Adversaries may connect to a remote system over RDP/RDS to expand access if the service is enabled and allows access to accounts with known credentials. Adversaries will likely use Credential Access techniques to acquire credentials to use with RDP. Adversaries may also use RDP in conjunction with the Accessibility Features or Terminal Services DLL for Persistence.
Audit
Audit the Remote Desktop Users group membership regularly. Remove unnecessary accounts and groups from Remote Desktop Users groups.
Disable or Remove Feature or Program
Disable the RDP service if it is unnecessary.
Limit Access to Resource Over Network
Use remote desktop gateways.
Multi-factor Authentication
Use multi-factor authentication for remote logins.
Network Segmentation
Do not leave RDP accessible from the internet. Enable firewall rules to block RDP traffic between network security zones within a network.
Operating System Configuration
Change GPOs to define shorter timeouts sessions and maximum amount of time any single session can be active. Change GPOs to specify the maximum amount of time that a disconnected session stays active on the RD session host server.
Privileged Account Management
Consider removing the local Administrators group from the list of groups allowed to log in through RDP.
User Account Management
Limit remote user permissions if remote access is necessary.
Monitoring the following activities in your Organization can help you detect this technique.
Logon Session: Logon Session Creation
Initial construction of a new user logon session (ex: Windows EID 4624, /var/log/utmp, or /var/log/wmtp)
Monitor for user accounts logged into systems associated with RDP (ex: Windows EID 4624 Logon Type 10). Other factors, such as access patterns (ex: multiple systems over a relatively short period of time) and activity that occurs after a remote login, may indicate suspicious or malicious behavior with RDP.
Network Traffic: Network Connection Creation
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Monitor for newly constructed network connections (typically over port 3389) that may use Valid Accounts to log into a computer using the Remote Desktop Protocol (RDP). The adversary may then perform actions as the logged-on user. Other factors, such as access patterns and activity that occurs after a remote login, may indicate suspicious or malicious behavior with RDP.
Network Traffic: Network Traffic Flow
Summarized network packet data, with metrics, such as protocol headers and volume (ex: Netflow or Zeek http.log)
Monitor network traffic for uncommon data flows that may use /techniques/T1078 to log into a computer using the Remote Desktop Protocol (RDP).
Process: Process Creation
Birth of a new running process (ex: Sysmon EID 1 or Windows EID 4688)
Monitor for newly executed processes (such as mstsc.exe) that may use Valid Accounts to log into a computer using the Remote Desktop Protocol (RDP). The adversary may then perform actions that spawn additional processes as the logged-on user.
The APT1 group is known to have used pass the hash.
Adversaries may "pass the hash" using stolen password hashes to move laterally within an environment, bypassing normal system access controls. Pass the hash (PtH) is a method of authenticating as a user without having access to the user's cleartext password. This method bypasses standard authentication steps that require a cleartext password, moving directly into the portion of the authentication that uses the password hash.
When performing PtH, valid password hashes for the account being used are captured using a Credential Access technique. Captured hashes are used with PtH to authenticate as that user. Once authenticated, PtH may be used to perform actions on local or remote systems.
Adversaries may also use stolen password hashes to "overpass the hash." Similar to PtH, this involves using a password hash to authenticate as a user but also uses the password hash to create a valid Kerberos ticket. This ticket can then be used to perform Pass the Ticket attacks.
Privileged Account Management
Limit credential overlap across systems to prevent the damage of credential compromise and reduce the adversary's ability to perform Lateral Movement between systems.
Update Software
Apply patch KB2871997 to Windows 7 and higher systems to limit the default access of accounts in the local administrator group.
User Account Control
Enable pass the hash mitigations to apply UAC restrictions to local accounts on network logon. The associated Registry key is located HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\LocalAccountTokenFilterPolicy.
Through GPO: Computer Configuration > [Policies] > Administrative Templates > SCM: Pass the Hash Mitigations: Apply UAC restrictions to local accounts on network logons.[18]
User Account Management
Do not allow a domain user to be in the local administrator group on multiple systems.
Monitoring the following activities in your Organization can help you detect this technique.
Active Directory: Active Directory Credential Request
A user requested active directory credentials, such as a ticket or token (ex: Windows EID 4769)
Monitor requests of new ticket granting ticket or service tickets to a Domain Controller. Windows Security events such as 4768 (A Kerberos authentication ticket (TGT) was requested) and 4769 (A Kerberos service ticket was requested) combined with logon session creation information may be indicative of an overpass the hash attempt.
Logon Session: Logon Session Creation
Initial construction of a new user logon session (ex: Windows EID 4624, /var/log/utmp, or /var/log/wmtp)
Monitor newly created logons and credentials used in events and review for discrepancies. Unusual remote logins that correlate with other suspicious activity (such as writing and executing binaries) may indicate malicious activity.
User Account: User Account Authentication
An attempt by a user to gain access to a network or computing resource, often by providing credentials (ex: Windows EID 4625 or /var/log/auth.log)
Monitor for user authentication attempts. From a classic Pass-The-Hash perspective, this technique uses a hash through the NTLMv1 / NTLMv2 protocol to authenticate against a compromised endpoint. This technique does not touch Kerberos. Therefore, NTLM LogonType 3 authentications that are not associated to a domain login and are not anonymous logins are suspicious. From an Over-Pass-The-Hash perspective, an adversary wants to exchange the hash for a Kerberos authentication ticket (TGT). One way to do this is by creating a sacrificial logon session with dummy credentials (LogonType 9) and then inject the hash into that session which triggers the Kerberos authentication process.
APT1 has collected files from a local victim.
Adversaries may search local system sources, such as file systems and configuration files or local databases, to find files of interest and sensitive data prior to Exfiltration.
Adversaries may do this using a Command and Scripting Interpreter, such as cmd as well as a Network Device CLI, which have functionality to interact with the file system to gather information. Adversaries may also use Automated Collection on the local system.
Data Loss Prevention
Data loss prevention can restrict access to sensitive data and detect sensitive data that is unencrypted.
Monitoring the following activities in your Organization can help you detect this technique.
Command: Command Execution
Invoking a computer program directive to perform a specific task (ex: Windows EID 4688 of cmd.exe showing command-line parameters, ~/.bash_history, or ~/.zsh_history)
Monitor executed commands and arguments that may search and collect local system sources, such as file systems or local databases, to find files of interest and sensitive data prior to Exfiltration. Remote access tools with built-in features may interact directly with the Windows API to gather data. Data may also be acquired through Windows system management tools such as Windows Management Instrumentation and PowerShell.
File: File Access
Opening a file, which makes the file contents available to the requestor (ex: Windows EID 4663)
Monitor for unexpected/abnormal access to files that may be malicious collection of local data, such as user files (pdf, .docx, .jpg, etc.) or local databases.
Process: OS API Execution
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Monitor for API calls that may search local system sources, such as file systems or local databases, to find files of interest and sensitive data prior to Exfiltration.
Process: Process Creation
Birth of a new running process (ex: Sysmon EID 1 or Windows EID 4688)
Monitor for newly executed processes that may search local system sources, such as file systems or local databases, to find files of interest and sensitive data prior to Exfiltration.
Script: Script Execution
Launching a list of commands through a script file (ex: Windows EID 4104)
Monitor for any attempts to enable scripts running on a system would be considered suspicious. If scripts are not commonly used on a system, but enabled, scripts running out of cycle from patching or other administrator functions are suspicious. Scripts should be captured from the file system when possible to determine their actions and intent. Data may also be acquired through Windows system management tools such as Windows Management Instrumentation and PowerShell.
APT1 uses two utilities, GETMAIL and MAPIGET, to steal email. GETMAIL extracts emails from archived Outlook .pst files.
Adversaries may target user email on local systems to collect sensitive information. Files containing email data can be acquired from a user’s local system, such as Outlook storage or cache files.
Outlook stores data locally in offline data files with an extension of .ost. Outlook 2010 and later supports .ost file sizes up to 50GB, while earlier versions of Outlook support up to 20GB. IMAP accounts in Outlook 2013 (and earlier) and POP accounts use Outlook Data Files (.pst) as opposed to .ost, whereas IMAP accounts in Outlook 2016 (and later) use .ost files. Both types of Outlook data files are typically stored in C:\Users\<username>\Documents\Outlook Files or C:\Users\<username>\AppData\Local\Microsoft\Outlook.
Encrypt Sensitive Information
Use of encryption provides an added layer of security to sensitive information sent over email. Encryption using public key cryptography requires the adversary to obtain the private certificate along with an encryption key to decrypt messages.
Monitoring the following activities in your Organization can help you detect this technique.
Command: Command Execution
Invoking a computer program directive to perform a specific task (ex: Windows EID 4688 of cmd.exe showing command-line parameters, ~/.bash_history, or ~/.zsh_history)
Monitor executed commands and arguments for actions that could be taken to gather local email files. Remote access tools with built-in features may interact directly with the Windows API to gather information. Information may also be acquired through Windows system management tools such as Windows Management Instrumentation and PowerShell.
File: File Access
Opening a file, which makes the file contents available to the requestor (ex: Windows EID 4663)
Monitor for unusual processes accessing local email files that may target user email on local systems to collect sensitive information.
APT1 uses two utilities, GETMAIL and MAPIGET, to steal email. MAPIGET steals email still on Exchange servers that has not yet been archived.
Adversaries may target an Exchange server, Office 365, or Google Workspace to collect sensitive information. Adversaries may leverage a user's credentials and interact directly with the Exchange server to acquire information from within a network. Adversaries may also access externally facing Exchange services, Office 365, or Google Workspace to access email using credentials or access tokens. Tools such as MailSniper can be used to automate searches for specific keywords.
Encrypt Sensitive Information
Use of encryption provides an added layer of security to sensitive information sent over email. Encryption using public key cryptography requires the adversary to obtain the private certificate along with an encryption key to decrypt messages.
Multi-factor Authentication
Use of multi-factor authentication for public-facing webmail servers is a recommended best practice to minimize the usefulness of usernames and passwords to adversaries.
Monitoring the following activities in your Organization can help you detect this technique.
Command: Command Execution
Invoking a computer program directive to perform a specific task (ex: Windows EID 4688 of cmd.exe showing command-line parameters, ~/.bash_history, or ~/.zsh_history)
Monitor executed commands and arguments for actions that may target an Exchange server, Office 365, or Google Workspace to collect sensitive information.
Logon Session: Logon Session Creation
Initial construction of a new user logon session (ex: Windows EID 4624, /var/log/utmp, or /var/log/wmtp)
Monitor for unusual login activity from unknown or abnormal locations, especially for privileged accounts (ex: Exchange administrator account).
Network Traffic: Network Connection Creation
Initial construction of a WMI object, such as a filter, consumer, subscription, binding, or provider (ex: Sysmon EIDs 19-21)
Monitor for newly constructed network connections that are sent or received by untrusted hosts.
APT1 used a batch script to perform a series of discovery techniques and saves it to a text file.
Once established within a system or network, an adversary may use automated techniques for collecting internal data. Methods for performing this technique could include use of a Command and Scripting Interpreter to search for and copy information fitting set criteria such as file type, location, or name at specific time intervals. In cloud-based environments, adversaries may also use cloud APIs, command line interfaces, or extract, transform, and load (ETL) services to automatically collect data. This functionality could also be built into remote access tools.
This technique may incorporate use of other techniques such as File and Directory Discovery and Lateral Tool Transfer to identify and move files, as well as Cloud Service Dashboard and Cloud Storage Object Discovery to identify resources in cloud environments.
Encrypt Sensitive Information
Encryption and off-system storage of sensitive information may be one way to mitigate collection of files, but may not stop an adversary from acquiring the information if an intrusion persists over a long period of time and the adversary is able to discover and access the data through other means. Strong passwords should be used on certain encrypted documents that use them to prevent offline cracking through Brute Force techniques.
Remote Data Storage
Encryption and off-system storage of sensitive information may be one way to mitigate collection of files, but may not stop an adversary from acquiring the information if an intrusion persists over a long period of time and the adversary is able to discover and access the data through other means.
Monitoring the following activities in your Organization can help you detect this technique.
Command: Command Execution
Invoking a computer program directive to perform a specific task (ex: Windows EID 4688 of cmd.exe showing command-line parameters, ~/.bash_history, or ~/.zsh_history)
Monitor executed commands and arguments for actions that could be taken to collect internal data.
File: File Access
Opening a file, which makes the file contents available to the requestor (ex: Windows EID 4663)
Monitor for unexpected files (i.e. .pdf, .docx, .jpg, etc.) viewed for collecting internal data.
Script: Script Execution
Launching a list of commands through a script file (ex: Windows EID 4104)
Monitor for any attempts to enable scripts running on a system would be considered suspicious. If scripts are not commonly used on a system, but enabled, scripts running out of cycle from patching or other administrator functions are suspicious. Scripts should be captured from the file system when possible to determine their actions and intent.
APT1 has used RAR to compress files before moving them outside of the victim network.
Adversaries may use utilities to compress and/or encrypt collected data prior to exfiltration. Many utilities include functionalities to compress, encrypt, or otherwise package data into a format that is easier/more secure to transport.
Adversaries may abuse various utilities to compress or encrypt data before exfiltration. Some third party utilities may be preinstalled, such as tar on Linux and macOS or zip on Windows systems. On Windows, diantz or makecab may be used to package collected files into a cabinet (.cab) file. diantz may also be used to download and compress files from remote locations (i.e. Remote Data Staging). Additionally, xcopy on Windows can copy files and directories with a variety of options.
Adversaries may use also third party utilities, such as 7-Zip, WinRAR, and WinZip, to perform similar activities.
Audit
System scans can be performed to identify unauthorized archival utilities.
Monitoring the following activities in your Organization can help you detect this technique.
Command: Command Execution
Invoking a computer program directive to perform a specific task (ex: Windows EID 4688 of cmd.exe showing command-line parameters, ~/.bash_history, or ~/.zsh_history)
Monitor executed commands and arguments for actions that will aid in compression or encrypting data that is collected prior to exfiltration, such as tar.
File: File Creation
Initial construction of a new file (ex: Sysmon EID 11)
Monitor newly constructed files being written with extensions and/or headers associated with compressed or encrypted file types. Detection efforts may focus on follow-on exfiltration activity, where compressed or encrypted files can be detected in transit with a network intrusion detection or data loss prevention system analyzing file headers.
Process: Process Creation
Birth of a new running process (ex: Sysmon EID 1 or Windows EID 4688)
Monitor for newly constructed processes and/or command-lines that aid in compression or encrypting data that is collected prior to exfiltration, such as 7-Zip, WinRAR, and WinZip.
Copyright © 2022 AshwinPro