Suspicious APT42 Command Obfuscation via Environment Variable Substitution and Call (via process_creation)

ATT&CK techniques

Execution

Recon
Resource Dev
Initial Access
Execution
- T1059.003Windows Command Shell
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects cmd.exe defining an environment variable and then re-invoking it through call with a character-removal substitution to reconstruct a hidden command such as curl. APT42 used this set and call pattern with variable substitution to obscure download commands from simple string inspection. Building commands from variable substitution at runtime is a deliberate obfuscation technique.

Reporting behind it

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Suspicious APT42 Command Obfuscation via Environment Variable Substitution and Call (via process_creation)

Pivot detection · T1059.003 · 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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