T1491.002sub-technique of T1491 Defacement

External Defacement

Windows · IaaS · Linux · macOSnothing on this site yetT1491.002 on attack.mitre.org

An adversary may deface systems external to an organization in an attempt to deliver messaging, intimidate, or otherwise mislead an organization or users. External Defacement may ultimately cause users to distrust the systems and to question/discredit the system’s integrity. Externally-facing websites are a common victim of defacement; often targeted by adversary and hacktivist groups in order to push a political message or spread propaganda.

MITRE ATT&CK 19.2, retrieved 2026-09-12

If this is happening now

1

Checklists and playbooks to open while the alert is still live.

how MITRE says to see it

Behavioral Detection of External Website Defacement across Platforms

  • Adversary modifies externally-facing web content by accessing and overwriting hosted HTML/JS/CSS files, typically following web shell deployment, credential abuse, or exploitation of web application vulnerabilities.
  • Adversary compromises a Linux-based web server and modifies hosted web files by exploiting upload vulnerabilities, remote code execution, or replacing index.html via SSH/webshell.
  • Adversary modifies web-facing content on macOS via web development environments like MAMP or misconfigured Apache instances, typically with access to the hosting user account or via persistence tools.
  • Adversary modifies content in cloud-hosted websites (e.g., AWS S3-backed, Azure Blob-hosted sites) by gaining access to management consoles or APIs and uploading altered HTML/JS files.

what reduces it

  • M1053 Data Backup. Consider implementing IT disaster recovery plans that contain procedures for taking regular data backups that can be used to restore organizational data. Ensure backups are stored off system and is protected from common methods adversaries may use to gain access and destroy the backups to prevent recovery.

the rest of T1491

The description, detection analytics and mitigations are reproduced from MITRE ATT&CK, version 19.2, under its terms of use. The checklists, hunts, labs and everything else linked here are this site’s.