Suspicious PowerShell UTF8 OutputEncoding Command Wrapper

ATT&CK techniques

Execution

Recon
Resource Dev
Initial Access
Execution
- T1059.001PowerShell
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects PowerShell command lines that set OutputEncoding to a UTF8 encoding object before running an inline command, the wrapper ChaosBot used for every shell command it executed. The Rust bot prefixed all remote commands with this OutputEncoding assignment to reliably capture and exfiltrate output over Discord. While some scripts set encoding, this exact inline pattern combined with remote command execution is suspicious.

Reporting behind it

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Suspicious PowerShell UTF8 OutputEncoding Command Wrapper

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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