Suspicious CLR Runtime Load into Non-DotNet Process via Injection

ATT&CK techniques

Priv Esc → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
- T1055Process Injection
Defense Evasion
- T1055Process Injection
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects the .NET common language runtime being loaded into processes that do not normally execute managed code such as Windows Explorer as described in the WithSecure lab where a C3 relay injected a Covenant Grunt into a host process. A CLR image loaded into a non managed host is a well known indicator of in memory .NET tradecraft and process injection used to run tooling stealthily.

Reporting behind it

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Suspicious CLR Runtime Load into Non-DotNet Process via Injection

Pivot detection · T1055 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

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