Suspicious certutil Decode or Remote Download

ATT&CK techniques

Defense Evasion → C2

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1140Deobfuscate/Decode Files or Information
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1105Ingress Tool Transfer
Exfiltration
Impact

What it detects

This rule detects certutil.exe being used to decode encoded payloads or to download remote files via its URL cache, a common living-off-the-land technique for retrieving and deobfuscating second-stage malware. Adversaries abuse this signed binary to bypass application controls and stage payloads while blending with legitimate certificate tooling.

Reporting behind it

Related detections9 linkedT1105 — drag to rearrange

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Suspicious Payload Download to Temp Directory by Simps Botnet (via process_creation)

Suspicious Remote Script Piped to Shell via Wget (via process_creation)

Suspicious certutil Decode or Remote Download

Pivot detection · T1105 · 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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