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Potential notify_on_release Container Escape Detected via Defend for Containers

This rule detects modification of the cgroup notify_on_release file from inside a container. When the notify_on_release flag is enabled (1) in a cgroup, then whenever the last task in the cgroup exits or attaches to…

Description

This rule detects modification of the cgroup notify_on_release file from inside a container. When the notify_on_release flag is enabled (1) in a cgroup, then whenever the last task in the cgroup exits or attaches to another cgroup, the command specified in the release_agent file is run and invoked from the host. A privileged container with SYS_ADMIN capabilities, enables a threat actor to mount a cgroup directory and modify the notify_on_release flag in order to take advantage of this feature, which could be used for further privilege escalation and container escapes to the host machine.

Detection logic

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Detection requirements

Platform
ContainersESXiLinuxWindows

The rule states no platform. This is derived from the ATT&CK technique it maps to.

Log source category
event_index

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