Suspicious In-Memory .NET Assembly Load via PowerShell Base64 Payload (via process_creation)

ATT&CK techniques

Execution → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
- T1059.001PowerShell
Persistence
Priv Esc
Defense Evasion
- T1620Reflective Code Loading
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects PowerShell decoding a Base64 blob and reflectively loading it as a .NET assembly directly in memory. TA547 used this fileless technique to run the Rhadamanthys stealer without writing the payload to disk.

Reporting behind it

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Suspicious In-Memory .NET Assembly Load via PowerShell Base64 Payload (via process_creation)

Pivot detection · T1059.001 · 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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