Elastic Security Detection Rules

Browser Extension Install

Last updated 9 days ago on 2025-05-05
Created 2 years ago on 2023-08-22

About

Identifies the install of browser extensions. Malicious browser extensions can be installed via app store downloads masquerading as legitimate extensions, social engineering, or by an adversary that has already compromised a system.
Tags
Domain: EndpointOS: WindowsUse Case: Threat DetectionTactic: PersistenceData Source: Elastic DefendData Source: Elastic EndgameData Source: SentinelOneData Source: SysmonData Source: Microsoft Defender for EndpointLanguage: eql
Severity
low
Risk Score
21
MITRE ATT&CK™

Persistence (TA0003)(opens in a new tab or window)

↳ Software Extensions (T1176)(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-*logs-m365_defender.event-*logs-sentinel_one_cloud_funnel.*logs-windows.sysmon_operational-*winlogbeat-*endgame-*
Related Integrations

endpoint(opens in a new tab or window)

m365_defender(opens in a new tab or window)

sentinel_one_cloud_funnel(opens in a new tab or window)

windows(opens in a new tab or window)

Query
file where host.os.type == "windows" and event.type : "creation" and
(
  /* Firefox-Based Browsers */
  (
    file.name : "*.xpi" and
    file.path : "?:\\Users\\*\\AppData\\Roaming\\*\\Profiles\\*\\Extensions\\*.xpi" and
    not
    (
      process.name : "firefox.exe" and
      file.name : ("langpack-*@firefox.mozilla.org.xpi", "*@dictionaries.addons.mozilla.org.xpi")
    )
  ) or
  /* Chromium-Based Browsers */
  (
    file.name : "*.crx" and
    file.path : "?:\\Users\\*\\AppData\\Local\\*\\*\\User Data\\Webstore Downloads\\*"
  )
)

Install detection rules in Elastic Security

Detect Browser Extension Install 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).