Limit Ad Tracking

What the ad tracking limiter does

This Automox Worklet™ disables Apple's personalized advertising framework on macOS endpoints. The Worklet detects the installed macOS version and applies the appropriate configuration to limit ad tracking data collection.

Apple's advertising framework collects detailed user interest and behavioral data to enable targeted advertisements. While personalized ads can be relevant to users, the underlying data mining poses privacy risks and the collected information can be combined with other metadata to identify users. This Worklet prevents that data collection by disabling the allowApplePersonalizedAdvertising setting on Big Sur (macOS 11) endpoints and the forceLimitAdTracking setting on Catalina (macOS 10.15) endpoints.

The Worklet applies these settings per logged-in user through the Apple preferences system (com.apple.AdLib.plist). Configuration changes take effect immediately, though endpoints running Big Sur require a reboot to see the changes reflected in the System Preferences GUI.

Why restrict advertising identifier access

Applications with access to the advertising identifier track user behavior across multiple apps and websites without explicit consent. The identifier enables advertisers to build detailed profiles revealing browsing habits, application usage patterns, and personal interests. Malicious applications exfiltrate this tracking data to profile users, sell behavioral information to data brokers, or identify high-value targets for social engineering attacks. Users have no visibility into which applications access the identifier or how the data gets used.

This Automox Worklet blocks applications from accessing the advertising identifier by disabling Apple's personalized advertising framework. You reduce data collection by third-party applications and help meet GDPR requirements to minimize personal data exposure. The approach demonstrates privacy-conscious endpoint configuration while reducing the value of endpoint compromise to attackers, since disabled tracking provides less behavioral data for harvesting. The control adds no performance overhead while significantly reducing personal information available through application APIs.

How ad tracking limitation works

1. Evaluation phase: The Worklet checks which macOS version is installed and reads the current ad tracking setting from the user's Apple preferences plist file (com.apple.AdLib.plist). For Big Sur, it checks the allowApplePersonalizedAdvertising value. For Catalina, it checks the forceLimitAdTracking value. If ad tracking is enabled, the evaluation exits with status 1 to trigger remediation.

2. Remediation phase: The Worklet uses the defaults command to write the disable flag to the user's preferences file. On Big Sur, it sets allowApplePersonalizedAdvertising to false. On Catalina, it sets forceLimitAdTracking to true. The Worklet executes these changes with elevated privileges as the logged-in user to maintain the settings persistence.

Ad tracking limitation requirements

• macOS Catalina (10.15) or newer (Big Sur, Monterey, Ventura, and later)

• Logged-in user session (Worklet operates in the context of the currently logged-in user)

• Elevated privileges to modify user preferences files

• Not compatible with macOS 10.14 (Mojave) or earlier

Expected advertising tracking behavior

After completion, macOS blocks applications from accessing the advertising identifier. Apps and websites receive a zero or null value when requesting the identifier, preventing cross-app and cross-site tracking. Users experience generic advertisements instead of personalized ads based on behavioral profiles. The advertising framework no longer collects or shares user interest data with advertisers.

Verify the setting on Big Sur and later by opening System Preferences > Security and Privacy > Privacy > Apple Advertising and confirming "Personalized Ads" is unchecked. On Catalina, check System Preferences > Security and Privacy > Privacy > Advertising and verify "Limit Ad Tracking" is enabled. Run defaults read com.apple.AdLib allowApplePersonalizedAdvertising on Big Sur (returns 0 when disabled) or defaults read com.apple.AdLib forceLimitAdTracking on Catalina (returns 1 when enabled). The setting persists across user logins and system reboots without requiring reapplication.

How to validate limit ad tracking changes

1. Run this Worklet on a pilot macOS endpoint and review evaluation output for limit ad tracking.

2. Confirm Automox activity logs show successful completion and exit code 0.

3. Verify endpoint state using checks aligned to evaluation script logic, such as bigSur, exit, else.

4. Validate remediation effects from script operations such as bigSur, sudo, else, then rerun evaluation for compliance.