{
  "family": "megasearch",
  "sample_count": 5,
  "category": "advanced_threat",
  "description": "BrowserModifier:Win32/Megasearch is a highly intrusive browser hijacker and adware component designed to forcibly alter a user's web browsing experience. It manipulates browser settings to redirect search queries through its own affiliated engines, injects unwanted advertisements, and tracks user browsing behavior to generate illicit Pay-Per-Click (PPC) revenue for its creators.<br><br><b>Understanding Megasearch</b><br>To an end-user, Megasearch manifests as a sudden, unwanted change to their browser's homepage, new tab page, and default search engine (often redirecting to a page that looks like a generic search portal, but is heavily laden with sponsored links). For a security team, it represents a breakdown in endpoint hygiene and a potential vector for more serious infections via malvertising.<br><br><b>Execution and Hijacking Mechanics</b><br>Megasearch is typically distributed via deceptive software bundles, fake software updates, or malicious browser extensions downloaded from third-party sites (`T1189`). Upon execution, it modifies the Windows Registry (`T1112`) and browser configuration files (e.g., Chrome's `Preferences` file or Firefox's `prefs.js`) to enforce its settings (`T1562.001`). It often installs a persistent browser extension (`T1176`) to monitor searches and ensure the hijacking cannot be easily reversed by the user. Advanced variants may also modify the shortcuts (LNK files) on the desktop or taskbar (`T1547.009`) to automatically launch the browser to the hijacked URL.<br><br><b>Indicators of Compromise & Impact</b><br>The impact is a degraded user experience, potential privacy violations (tracking of search queries), and exposure to potentially malicious ads. Host-based IoCs include EDR alerts for modifications to browser shortcut properties or unexpected additions to Chrome/Firefox extension directories. Network IoCs include DNS queries resolving to the Megasearch infrastructure and redirected search traffic containing tracking parameters.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1547.009",
    "T1562.001",
    "T1112",
    "T1176"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1176",
      "name": "Browser Extensions (Installing malicious add-ons)",
      "tactic": "Persistence"
    },
    {
      "id": "T1112",
      "name": "Modify Registry (Changing default search/homepage keys)",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1562.001",
      "name": "Impair Defenses: Disable or Modify Tools (Browser hijacking)",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1547.009",
      "name": "Boot or Logon Autostart Execution: Shortcut Modification",
      "tactic": "Persistence"
    }
  ],
  "containment_steps": [
    "Remove any unknown or recently installed browser extensions from Chrome, Edge, and Firefox.",
    "Reset all installed web browsers to their default settings to clear out hijacked homepages, search engines, and modified preferences.",
    "Check all browser shortcut properties (Desktop, Taskbar, Start Menu) to ensure the 'Target' field has not been appended with a Megasearch URL.",
    "Run a thorough scan with an enterprise-grade Adware/PUA removal tool to clean up deep registry persistence mechanisms."
  ],
  "what_to_avoid": [
    "Do not simply change the homepage back manually; if the Megasearch extension or shortcut modification is still present, the changes will revert on the next launch.",
    "Avoid allowing users to download software from unverified third-party portals, as this is the primary vector for browser hijackers."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}