Understanding Attacks Linked to
APT17

Presented by: Ashwin (Microsoft Azure MVP)

APT17 is a China-based threat group that has conducted network intrusions against U.S. government entities, the defense industry, law firms, information technology companies, mining companies, and non-government organizations.

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.

Acquire Infrastructure

Resource Development

Web Services

APT17 has created profile pages in Microsoft TechNet that were used as C2 infrastructure.

Adversaries may register for web services that can be used during targeting. A variety of popular websites exist for adversaries to register for a web-based service that can be abused during later stages of the adversary lifecycle, such as during Command and Control (Web Service) or Exfiltration Over Web Service. Using common services, such as those offered by Google or Twitter, makes it easier for adversaries to hide in expected noise. By utilizing a web service, adversaries can make it difficult to physically tie back operations to them.

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.

Internet Scan: Response Content

Logged network traffic in response to a scan showing both protocol header and body values

Once adversaries leverage the web service as infrastructure (ex: for command and control), it may be possible to look for unique characteristics associated with adversary software, if known. 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 (Web Service) or Exfiltration Over Web Service.

Establish Accounts

Resource Development

APT17 has created and cultivated profile pages in Microsoft TechNet. To make profile pages appear more legitimate, APT17 has created biographical sections and posted in forum threads.

Adversaries may create and cultivate accounts with services that can be used during targeting. Adversaries can create accounts that can be used to build a persona to further operations. Persona development consists of the development of public information, presence, history and appropriate affiliations. This development could be applied to social media, website, or other publicly available information that could be referenced and scrutinized for legitimacy over the course of an operation using that persona or identity.

For operations incorporating social engineering, the utilization of an online persona may be important. These personas may be fictitious or impersonate real people. The persona may exist on a single site or across multiple sites (ex: Facebook, LinkedIn, Twitter, Google, GitHub, Docker Hub, etc.). Establishing a persona may require development of additional documentation to make them seem real. This could include filling out profile information, developing social networks, or incorporating photos.

Establishing accounts can also include the creation of accounts with email providers, which may be directly leveraged for Phishing for Information or Phishing.

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.

Network Traffic: Network Traffic Content

Logged network traffic data showing both protocol header and body values (ex: PCAP)

Monitor and analyze 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)).

Persona: Social Media

Established, compromised, or otherwise acquired social media personas

Consider monitoring social media activity related to your organization. Suspicious activity may include personas claiming to work for your organization or recently created/modified accounts making numerous connection requests to accounts affiliated with your organization.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).