Detection Strategy for Resource Forking on macOS

Technique Detected:  Resource Forking | T1564.009

ID: DET0584
Domains: Enterprise
Analytics: AN1609
Version: 1.0
Created: 21 October 2025
Last Modified: 21 October 2025

Analytics

AN1609

Unexpected creation or modification of files with com.apple.ResourceFork extended attributes containing unusually large or non-standard data. Defender perspective: detection of resource forks in contexts where they are uncommon, especially when paired with process execution or network activity.

Log Sources
Data Component Name Channel
File Metadata (DC0059) macos:unifiedlog File creation or modification with com.apple.ResourceFork extended attribute
Command Execution (DC0064) macos:unifiedlog Execution of commands like `ls -l@`, `xattr -l`, or custom tools interacting with resource forks
Process Creation (DC0032) macos:unifiedlog Process creation involving binaries interacting with resource fork data
Mutable Elements
Field Description
ResourceForkSizeThreshold Adjust thresholds for 'unusually large' resource fork data based on baseline usage in the environment.
MonitoredDirectories Scope monitoring to sensitive directories such as /Users, /Applications, or temporary paths.
CorrelatedActivityWindow Time window for correlating resource fork activity with subsequent execution or network activity.