Malicious Payload Decryption via openssl AES-256-CBC

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 openssl being used to decrypt an AES-256-CBC base64 payload with a supplied password, the deobfuscation routine used by macOS Shlayer and Bundlore adware to unpack their next stage. Attackers ship encrypted shell payloads and decode them at runtime to evade static detection before execution.

Reporting behind it

Related detections9 linkedT1140 — drag to rearrange

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Suspicious Python Inline Deobfuscation and Execution One-Liner

Suspicious Base64 Decoded Payload Piped to Shell on Linux

Malicious Payload Decryption via openssl AES-256-CBC

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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