MITRE ATT&CK · T1176

Software Extensions

MITRE · cited in 14 of our lessons

Explanation

What attackers do. Attackers abuse software extensions, such as browser extensions or plugins for editors and other applications, to keep access, steal data or run code. Extensions run with the trust of the host application and can see what the user sees. This serves Persistence.

How to defend. Manage browser and development tool extensions centrally with allowlists, block installation from outside official stores and review permissions requested by approved extensions. Watch for updates that change an extension's behaviour or owner. Inventory installed extensions across endpoints regularly.

Signs to look for. Look for extensions installed outside policy, extensions requesting access to all sites or cookies, sudden permission changes after an update, and extension processes contacting unknown domains. A common gap is having no inventory of extensions at all.

The official text
Adversaries may abuse software extensions to establish persistent access to victim systems. Software extensions are modular components that enhance or customize the functionality of software applications, including web browsers, Integrated Development Environments (IDEs), and other platforms. Extensions are typically installed via official marketplaces, app stores, or manually loaded by users, and they often inherit the permissions and access levels of the host application. Malicious extensions can be introduced through various methods, including social engineering, compromised marketplaces, or direct installation by users or by adversaries who have already gained access to a system. Malicious extensions can be named similarly or identically to benign extensions in marketplaces. Security mechanisms in extension marketplaces may be insufficient to detect malicious components, allowing adversaries to bypass automated scanners or exploit trust established during the installation process. Adversaries may also abuse benign extensions to achieve their objectives, such as using legitimate functionality to tunnel data or bypass security controls. The modular nature of extensions and their integration with host applications make them an attractive target for adversaries seeking to exploit trusted software ecosystems. Detection can be challenging due to the inherent trust placed in extensions during installation and their ability to blend into normal application workflows.

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Lessons that cite it

Real incidents where this item mattered: the latest 12 of 14.