Query: EDR alert: possible Browser Extensions (T1176.001)
Matching passage: T1176.001 Browser Extensions. Tactics: persistence. Description: Adversaries may abuse internet browser extensions to establish persistent access to victim systems. Browser extensions or plugins are small programs that can add functionality to and customize aspects of internet browsers. They can be installed directly via a local file or custom URL or through a browser's app store - an official online platform where users can browse, install, and manage extensions for a specific web browser. Extensions generally inherit the web browser's permissions previously granted.(Citation: Wikipedia Browser Extension)(Citation: Chrome Extensions Definition) Malicious extensions can be installed into a browser through malicious app store downloads masquerading as legitimate extensions, through social engineering, or by an adversary that has already compromised a system. Security can be limited on browser app stores, so it may not be difficult for malicious extensions to defeat automated scanners.(Citation: Malicious Chrome Extension Numbers) Depending on the browser, adversaries may also manipulate an extension's update url to install updates from an adversary-controlled server or manipulate the mobile configuration file to silently install additional extensions. Adversaries may abuse how chromium-based browsers load extensions by modifying or replacing the Preferences and/or Secure Preferences files to silently install malicious extensions. When the browser is not running, adversaries can alter these files, ensuring the extension is loaded, granted desired permissions, and will persist in browser sessions. This method does not require user consent and extensions are silently loaded in the background from disk or from the browser's trusted store.(Citation: Pulsedive) Previous to macOS 11, adversaries could silently install browser extensions via the command line using the <code>profiles</code> tool to install malicious <code>.mobileconfig</code> files. In macOS 11+, the use of the <code>profiles</code> tool can no longer install configuration
Near-miss passage: T1176.002 IDE Extensions. Tactics: persistence. Description: Adversaries may abuse an integrated development environment (IDE) extension to establish persistent access to victim systems.(Citation: Mnemonic misuse visual studio) IDEs such as Visual Studio Code, IntelliJ IDEA, and Eclipse support extensions - software components that add features like code linting, auto-completion, task automation, or integration with tools like Git and Docker. A malicious extension can be installed through an extension marketplace (i.e., [Compromise Software Dependencies and Development Tools](https://attack.mitre.org/techniques/T1195/001)) or side-loaded directly into the IDE.(Citation: Abramovsky VSCode Security)(Citation: Lakshmanan Visual Studio Marketplace) In addition to installing malicious extensions, adversaries may also leverage benign ones. For example, adversaries may establish persistent SSH tunnels via the use of the VSCode Remote SSH extension (i.e., [IDE Tunneling](https://attack.mitre.org/techniques/T1219/001)). Trust is typically established through the installation process; once installed, the malicious extension is run every time that the IDE is launched. The extension can then be used to execute arbitrary code, establish a backdoor, mine cryptocurrency, or exfiltrate data.(Citation: ExtensionTotal VSCode Extensions 2025)