Obfuscated File Decoding via Certutil (via process_creation)

ATT&CK techniques

Defense Evasion

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

What it detects

This rule detects certutil being used with its decode flags to convert a base64 or hex-encoded file back into an executable payload, a deobfuscation step adversaries use to reconstruct malware from a benign-looking encoded file. Certutil deobfuscation is a defense-evasion technique in the Red Canary Threat Detection Report because it hides payloads from content inspection in transit. Detecting decode invocations surfaces payload staging under a trusted binary.

Reporting behind it

Related detections9 linkedT1140 — drag to rearrange

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Suspicious File Download via certutil URLCache (via process_creation)

Suspicious Base64 Decoding Piped to Shell on macOS

Suspicious Hex Decoding Piped to Shell via xxd on macOS

Malicious GitVenom Python Fernet Decrypt-and-Execute Loader via process_creation

Certutil Decoding Encoded Payload to Executable

Obfuscated File Decoding via Certutil (via process_creation)

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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