T1563 - Remote Service Session Hijacking

Adversaries may take control of preexisting sessions with remote services to move laterally in an environment. Users may use valid credentials to log into a service specifically designed to accept remote connections, such as telnet, SSH, and RDP. When a user logs into a service, a session will be established that will allow them to maintain a continuous interaction with that service.

Adversaries may commandeer these sessions to carry out actions on remote systems. Remote Service Session Hijacking differs from use of Remote Services because it hijacks an existing session rather than creating a new session using Valid Accounts.(Citation: RDP Hijacking Medium)(Citation: Breach Post-mortem SSH Hijack)

Atomic Tests:

Currently, no tests are available for this technique.

Detection

Use of these services may be legitimate, depending upon the network environment and how it is used. Other factors, such as access patterns and activity that occurs after a remote login, may indicate suspicious or malicious behavior with that service. Monitor for user accounts logged into systems they would not normally access or access patterns to multiple systems over a relatively short period of time.

Monitor for processes and command-line arguments associated with hijacking service sessions.

Shield Active Defense

Behavioral Analytics

Deploy tools that detect unusual system or user behavior.

Instrument a system to collect detailed information about process execution and user activity, develop a sense of normal or expected behaviors, and alert on abnormal or unexpected activity. This can be accomplished either onboard the target system or by shipping data to a centralized analysis and alerting system.

Opportunity

There is an opportunity to detect the presence of an adversary by identifying and alerting on anomalous behaviors.

Use Case

A defender can look for anomalies in accounts being active with other services/systems during hours they are normally not active. This can indicate malicious activity.

Procedures

Use behavioral analytics to detect Living Off The Land Binaries (LOLBins) being used to download and execute a file. Use behavioral analytics to identify a system running development tools, but is not used by someone who does development. Use behavioral analytics to identify abnormal system processes being used to launch a different process.