Suspicious Cabinet Extraction of Masqueraded vstm Archive via extrac32

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1140Deobfuscate/Decode Files or Information
- T1218System Binary Proxy Execution
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects extrac32.exe extracting a cabinet archive that uses a deceptive vstm extension. This delivery step was observed in CastleLoader and LummaStealer fake installer campaigns to unpack staged components.

Reporting behind it

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Suspicious Cabinet Extraction of Masqueraded vstm Archive via extrac32

Pivot detection · T1140 · 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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