Suspicious Double Base64 Decoded Payload Piped to Shell in CI (reviewdog Supply Chain)

ATT&CK techniques

Initial Access → Cred Access

Recon
Resource Dev
Initial Access
- T1195.002Compromise Software Supply Chain
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
- T1552.001Credentials In Files
- T1552.004Private Keys
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects a base64 decoded payload being piped directly into a shell, the execution pattern of the injected reviewdog/action-setup install.sh that dumped CI runner memory. It matters because decode into shell in a build step is a common way supply chain payloads execute credential theft code without touching disk.

Reporting behind it

Related detections9 linkedT1552.001 — drag to rearrange

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Malicious TeamPCP durabletask Payload python3 managed.pyz from tmp (via process_creation)

Suspicious Process Memory Read from Proc Mem for Secret Extraction

Suspicious Access to Cloud and Database Credential Files via Process

Suspicious Credential Exfiltration to webhook.site (via dns_query)

Malicious PowerShell Download from bullethost.cloud Staging Server

Suspicious Double Base64 Decoded Payload Piped to Shell in CI (reviewdog Supply Chain)

Pivot detection · T1552.001 · 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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