Malicious macOS Payload Download and Execution via curl Piped to zsh

ATT&CK techniques

Execution → C2

Recon
Resource Dev
Initial Access
Execution
- T1059.004Unix Shell
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1105Ingress Tool Transfer
Exfiltration
Impact

What it detects

This rule detects a remote payload being downloaded with curl and immediately piped into the zsh or sh shell for execution on macOS. This loader behavior was used by the MacSync stealer and RAT documented by Huntress to fetch and run its second stage without touching disk. Piping downloaded content straight into an interpreter is a hallmark of fileless staging and warrants investigation.

Reporting behind it

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Malicious macOS Payload Download and Execution via curl Piped to zsh

Pivot detection · T1059.004 · 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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