Malicious IIS Worker Process Spawning Command Shell for Webshell Reconnaissance (via process_creation)

ATT&CK techniques

Execution → Persistence

Recon
Resource Dev
Initial Access
Execution
- T1059.001PowerShell
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 cmd.exe, the webshell execution behavior Red Canary observed during a hospital ransomware intrusion where the shell ran net.exe reconnaissance before lateral movement and Cobalt Strike deployment. A web server worker launching an interactive command shell is a strong sign of a deployed webshell running operating-system commands, making early detection critical for catching post-exploitation before ransomware.

Reporting behind it

Related detections9 linkedT1059.001 — drag to rearrange

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Malicious IIS Worker Process Spawning Command Shell for Webshell Reconnaissance (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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