Quarantine Attrib Removed by Unsigned or Untrusted Process

Last updated 2 months ago on 2025-03-18

Created 5 years ago on 2020-08-14

About

Detects deletion of the quarantine attribute by an unusual process (xattr). In macOS, when applications or programs are downloaded from the internet, there is a quarantine flag set on the file. This attribute is read by Apple's Gatekeeper defense program at execution time. An adversary may disable this attribute to evade defenses.

Tags

Domain: EndpointOS: macOSUse Case: Threat DetectionTactic: Defense EvasionData Source: Elastic DefendLanguage: eql

Severity

medium

Risk Score

MITRE ATT&CK™

Defense Evasion (TA0005)(opens in a new tab or window)

↳ Impair Defenses (T1562)(opens in a new tab or window)

License

Elastic License v2(opens in a new tab or window)

Definition

Rule Type: Event Correlation Rule
Integration Pack: Prebuilt Security Detection Rules
Index Patterns: logs-endpoint.events.file*
Related Integrations: endpoint(opens in a new tab or window)
Query

file where event.action == "extended_attributes_delete" and host.os.type == "macos" and process.executable != null and
 (process.code_signature.trusted == false or process.code_signature.exists == false) and 
 not process.executable like ("/usr/bin/xattr",
                              "/System/*",
                              "/private/tmp/KSInstallAction.*/*/Install Google Software Update.app/Contents/Helpers/ksinstall",
                              "/Applications/CEWE Fotoschau.app/Contents/MacOS/FotoPlus",
                              "/Applications/.com.bomgar.scc.*/Remote Support Customer Client.app/Contents/MacOS/sdcust") and 
 not file.path like "/private/var/folders/*"

Install detection rules in Elastic Security

Detect Quarantine Attrib Removed by Unsigned or Untrusted Process in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).