{
  "family": "whimoo",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nWhimoo is a prevalent adware family and Potentially Unwanted Program (PUP) designed to aggressively monetize an infected user's web browsing activity. It achieves this by modifying core browser configurations, injecting intrusive advertisements, and tracking user data, severely degrading both system performance and user privacy.\n\n<h3>Distribution and Technical Behavior</h3>\nWhimoo is almost exclusively distributed via deceptive software bundling. Users inadvertently infect their systems when downloading \"free\" software—such as media players, PDF converters, or system optimizers—from untrustworthy software aggregation websites, where Whimoo is hidden in the \"Recommended\" installation path.\n\nOnce installed, Whimoo deeply integrates with the operating system and installed web browsers (Google Chrome, Mozilla Firefox, Microsoft Edge). Its core behaviors include:\n<ul>\n<li><strong>Browser Hijacking:</strong> Forcibly altering the default search engine, homepage, and new tab settings to redirect all traffic through an affiliate-linked search portal controlled by the adware operators.</li>\n<li><strong>Ad Injection:</strong> Utilizing malicious browser extensions or local proxy settings to overlay legitimate websites with intrusive pop-ups, pop-unders, banner ads, and sponsored in-text hyperlinks.</li>\n<li><strong>Data Harvesting:</strong> Continuously tracking the user's browsing history, search terms, and geolocation data to serve highly targeted advertisements and to sell this telemetry to third-party data brokers.</li>\n</ul>\n\n<h3>Risk Assessment</h3>\nWhile Whimoo is not classified as destructive malware (it does not encrypt files or steal banking credentials), it introduces significant operational friction. The injected advertisements are frequently served by low-reputation ad networks, increasing the likelihood of \"malvertising\" attacks that can lead to severe secondary infections, such as ransomware or info-stealers.\n\n<h3>Mitigation and Removal Strategies</h3>\n<ul>\n<li><strong>Browser Remediation:</strong> Manually inspect and remove any unknown or unauthorized extensions from all installed web browsers. Perform a complete factory reset of the browsers to clear hijacked search and homepage configurations.</li>\n<li><strong>Endpoint Scanning:</strong> Utilize a reputable enterprise-grade anti-malware solution to perform a deep system scan, targeting the Whimoo executables, hidden scheduled tasks, and persistent registry keys.</li>\n<li><strong>Application Control:</strong> Enforce strict application whitelisting policies (e.g., Windows Defender Application Control) to prevent standard users from executing unapproved software installers that frequently bundle adware.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Adware.Whimoo",
    "PUP.Whimoo",
    "BrowserModifier.Whimoo"
  ],
  "enrichment_level": "insufficient_information",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1566.002",
    "T1176",
    "T1112"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-07-01T16:13:06Z",
  "type": "Adware",
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}