Malicious IIS Worker Process Spawning Command Shell via process_creation

ATT&CK techniques

Execution → Persistence

Recon
Resource Dev
Initial Access
Execution
- T1059.003Windows Command Shell
Persistence
- T1505.003Web Shell
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects the IIS worker process w3wp.exe spawning a command interpreter, PowerShell or certutil which is a strong indicator of web shell command execution on a compromised web server. Kaspersky observed a Behinder web shell driving w3wp.exe to launch cmd.exe and download follow-on payloads. Web shell to shell transitions are an early sign of hands-on-keyboard server intrusion.

Reporting behind it

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Malicious IIS Worker Process Spawning Command Shell via process_creation

Pivot detection · T1505.003 · 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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