{
  "family": "pullupdate",
  "sample_count": 7,
  "category": "advanced_threat",
  "description": "Adware:Win32/Pullupdate is a persistent component often associated with larger Potentially Unwanted Program (PUA) or Adware frameworks. Its primary function is to act as a silent, background updater service. Rather than delivering a payload itself, Pullupdate ensures that any previously installed adware extensions, browser hijackers, or tracking modules on the endpoint are constantly refreshed, overriding any user attempts to remove or disable them.<br><br><b>Understanding Pullupdate Mechanisms</b><br>To an end-user, Pullupdate is entirely invisible; it doesn't display windows or generate errors. However, users will notice that rogue browser extensions (like 'Search Protect' or various coupon clippers) miraculously reappear after being deleted. For a security analyst, Pullupdate is a persistence mechanism (`T1547.001`). It is the 'watchdog' that guarantees the adware developers maintain their foothold on the system to continue generating illicit affiliate revenue.<br><br><b>Execution and Persistence</b><br>Pullupdate is installed silently alongside bundled freeware (`T1189`). It immediately registers itself as a Windows Service (`T1543.003`) or creates a scheduled task (`T1053.005`) that runs with SYSTEM privileges upon boot. Once active, it periodically reaches out to its Command-and-Control (C2) servers (`T1071.001`). It downloads the latest versions of the adware binaries and rogue browser extension `.crx` files. If it detects that the adware has been removed from the browser or the registry, it silently reinstalls it (`T1176`), effectively undoing the user's remediation efforts.<br><br><b>Indicators of Compromise & Impact</b><br>The primary impact is the inability to permanently remove adware, leading to continuous browser hijacking and privacy violations. IoCs include EDR alerts for the creation of unexpected Scheduled Tasks pointing to obscure executables in the `%AppData%` or `%ProgramData%` directories. Network logs will show rhythmic, beaconing HTTP/HTTPS traffic to known PUA infrastructure, often downloading signed, but suspicious, payload files.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1543.003",
    "T1176",
    "T1053.005",
    "T1189"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1543.003",
      "name": "Create or Modify System Process: Windows Service (Updater service)",
      "tactic": "Persistence"
    },
    {
      "id": "T1053.005",
      "name": "Scheduled Task/Job: Scheduled Task",
      "tactic": "Persistence"
    },
    {
      "id": "T1176",
      "name": "Browser Extensions (Reinstalling rogue extensions)",
      "tactic": "Persistence"
    },
    {
      "id": "T1189",
      "name": "Drive-by Compromise (Initial delivery)",
      "tactic": "Initial Access"
    }
  ],
  "containment_steps": [
    "Do not simply delete the adware extension from the browser; you must first locate and neutralize the Pullupdate service or task, otherwise the extension will return on reboot.",
    "Audit the Windows Task Scheduler (`taskschd.msc`) and Services (`services.msc`) for entries created around the time the adware first appeared.",
    "Deploy an enterprise-grade PUA removal tool (like AdwCleaner) to surgically remove the updater service and all associated registry keys.",
    "Block the known C2 domains associated with the adware family at the perimeter firewall to prevent the updater from downloading fresh payloads."
  ],
  "what_to_avoid": [
    "Avoid assuming manual deletion of a file fixes the problem; updater components are specifically designed to survive basic deletion attempts.",
    "Do not ignore recurring adware alerts from the same machine; it indicates the underlying updater mechanism is still active."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}