TA0005 · DEFENSE EVASION
Modify System Image
Adversaries may make changes to the operating system of embedded network devices to weaken defenses and provide new capabilities for themselves.
Detect it with
Most embedded network devices provide a command to print the version of the currently running operating system. Use this command to query the operating system for its version number and compare it to what is expected for the device in question.
Why it matters on shift
Modify System Image is one of the concrete ways adversaries achieve defense evasion. Recognising it in telemetry lets you name the technique in your ticket and pivot to what came before and after.
What to look for next
After defense evasion, the next tactic is usually Credential Access. Search your telemetry for the transition before closing the ticket.
2 sub-techniques
How it shows up in practice
- T1601.001
Patch System Image
Adversaries may modify the operating system of a network device to introduce new capabilities or weaken existing defenses.
- T1601.002
Downgrade System Image
Adversaries may install an older version of the operating system of a network device to weaken security. Older operating system versions on network devices often have weaker encryption ciphers and, in general, fewer/less updated defensive features.
Kill-chain context