Malicious Sapphire Sleet curl to osascript Chain With mac-cur User-Agent (via process_creation)

ATT&CK techniques

Execution → C2

Recon
Resource Dev
Initial Access
Execution
- T1059.002AppleScript
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1071.001Web Protocols
Exfiltration
Impact

What it detects

This rule detects a curl download piped into osascript while using the distinctive mac-cur user-agent, the staged execution chain Sapphire Sleet uses after a fake software update to fetch and run AppleScript payloads on macOS. Adversaries use this pattern to pull second-stage code and execute it in memory, so the mac-cur marker combined with curl and osascript exposes the intrusion at the download-and-execute stage.

Reporting behind it

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Malicious Sapphire Sleet curl to osascript Chain With mac-cur User-Agent (via process_creation)

Pivot detection · T1071.001 · 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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