Description
During the boot process, macOS executes <code>source /etc/rc.common</code>, which is a shell script containing various utility functions. This file also defines routines for processing command-line arguments and for gathering system settings, and is thus recommended to include in the start of Startup Item Scripts (Citation: Startup Items). In macOS and OS X, this is now a deprecated technique in favor of launch agents and launch daemons, but is currently still used. Adversaries can use the rc.common file as a way to hide code for persistence that will execute on each reboot as the root user (Citation: Methods of Mac Malware Persistence).
Threat-Mapped Scoring
Threat Score:
1.8
Industry:
Threat Priority:
P4 - Informational (Low)
ATT&CK Kill Chain Metadata
- Tactics: persistence
- Platforms: macOS
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Detection Guidance:
The <code>/etc/rc.common</code> file can be monitored to detect changes from the company policy. Monitor process execution resulting from the rc.common script for unusual or unknown applications or behavior.