{
  "family": "baidusearch",
  "sample_count": 2,
  "category": "advanced_threat",
  "description": "Adware:Win32/Baidusearch is a regional Potentially Unwanted Program (PUP) categorized as a Browser Hijacker, specifically targeting users in Asian markets. It aggressively manipulates browser settings to redirect the default search engine, homepage, and new tab page to Baidu (or affiliated third-party search portals). Its goal is to generate illicit Pay-Per-Click (PPC) revenue and track user search queries without explicit consent.<br><br><b>Understanding Baidusearch (Browser Hijackers)</b><br>To an end-user, Baidusearch manifests as a sudden inability to use their preferred search engine (like Google or Bing); every query is forcibly routed through Baidu, often accompanied by injected sponsored links. For a security team, it represents a breakdown in endpoint hygiene, a localized compliance violation, and a potential vector for data tracking (`T1185`).<br><br><b>Execution and Hijacking Mechanics</b><br>Baidusearch is typically distributed via deceptive software bundles (`T1189`), often packaged alongside legitimate freeware popular in Chinese-speaking regions. Upon execution, it aggressively modifies the Windows Registry (`T1112`) and browser configuration files (like Chrome's `Preferences` file) to enforce its settings (`T1562.001`). To prevent easy removal, it often installs persistent browser extensions or scheduled tasks (`T1547.001`) that actively monitor the browser settings and revert any changes the user makes back to the hijacked state.<br><br><b>Indicators of Compromise & Impact</b><br>The impact is a severely degraded user experience and potential privacy violations due to unauthorized search tracking. Host-based IoCs include EDR alerts for modifications to browser shortcut properties (appending the search URL to the target path), unexpected additions to browser extension directories, and registry modifications targeting `Software\\Microsoft\\Internet Explorer\\Main\\Start Page`. Network IoCs include DNS queries consistently resolving to specific search redirectors.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1189",
    "T1112",
    "T1562.001"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "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": "T1189",
      "name": "Drive-by Compromise (Software bundling)",
      "tactic": "Initial Access"
    }
  ],
  "containment_steps": [
    "Use the Windows Control Panel to thoroughly uninstall the explicitly named adware program and the freeware application that bundled it.",
    "Remove any unknown or recently installed browser extensions from all installed browsers (Chrome, Edge, Firefox).",
    "Reset all web browsers to their default settings to clear out hijacked homepages, search engines, and modified shortcut properties.",
    "Run a thorough scan with an enterprise-grade Adware/PUA removal tool to clean up deep registry persistence and watchdog tasks."
  ],
  "what_to_avoid": [
    "Do not simply change the homepage back manually in the browser settings; the persistent watchdog task will revert it on the next launch.",
    "Avoid allowing users to download software from unverified, regional third-party portals."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}