{
  "family": "gupd",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nGupd is a malicious Trojan (often functioning as a downloader or backdoor) that leverages social engineering by masquerading as a legitimate software update—frequently mimicking the \"Google Update\" (gupdate.exe) service or generic Windows updates. Its primary objective is to trick the user or the operating system into executing its payload, thereby establishing persistent, remote access for an attacker.\n\n<h3>Infection Vector and Technical Capabilities</h3>\nGupd is heavily reliant on deceptive distribution. It is often served via compromised \"watering hole\" websites (where users are prompted to \"Update Chrome to view this content\"), malvertising, or bundled within pirated software.\n\nOnce executed, Gupd focuses on blending in with normal system operations:\n<ul>\n<li><strong>Process Masquerading:</strong> The malware renames its executable to `gupd.exe`, `gupdate.exe`, or `wuauclt.exe`. It often drops itself into legitimate-looking directories (like `C:\\ProgramData\\Google\\` or `%AppData%\\Microsoft\\`) to evade casual inspection by the user or basic antivirus heuristics.</li>\n<li><strong>Persistence via Scheduled Tasks:</strong> To ensure it runs automatically, Gupd frequently creates Windows Scheduled Tasks named \"GoogleUpdateTaskMachineUA\" or similar, ensuring the malicious code executes with system privileges every time the computer boots or a user logs in.</li>\n<li><strong>C2 Communication and Payload Delivery:</strong> Under the guise of checking for updates, Gupd establishes an outbound connection to an attacker-controlled server. This channel is then used to silently download and execute secondary payloads, such as banking trojans, cryptominers, or info-stealers.</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nA Gupd infection is a severe security incident. By successfully masquerading as a trusted service, it bypasses user suspicion and often circumvents host-based firewalls that allow \"updater\" processes to communicate externally. Its presence indicates that secondary, highly destructive malware is likely already present on the system.\n\n<h3>Incident Response and Remediation</h3>\n<ul>\n<li><strong>Network Isolation and Process Termination:</strong> Immediately isolate the host. Utilize Task Manager or EDR tools to identify the rogue updater process. Pay close attention to the file path; a legitimate Google update will not run from the user's `Temp` directory. Terminate the process.</li>\n<li><strong>Eradicate Persistence Mechanisms:</strong> Thoroughly audit Windows Scheduled Tasks and the Registry `Run` keys. Delete any tasks or keys pointing to the malicious executable.</li>\n<li><strong>Comprehensive System Sweep:</strong> Because Gupd acts as a downloader, eradicating the initial loader is insufficient. Run a full, deep scan with an enterprise EDR solution to hunt for and remove the secondary payloads (e.g., keyloggers or ransomware staging files) it likely deployed.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Trojan.Gupd",
    "FakeUpdate.Gupd",
    "Win32/Gupd"
  ],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Gupd and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Gupd is classified as a Ransomware. Documented across security telemetry, it is engineered to execute unauthorized operations, establish persistent footholds on target endpoints, and facilitate malicious campaigns targeting enterprise and individual environments."
      }
    },
    {
      "@type": "Question",
      "name": "How does Gupd establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Gupd typically establishes persistence through registry run keys, scheduled tasks, or service installations, while evading signature-based antivirus solutions through code obfuscation, memory injection, or anti-analysis sandbox checks."
      }
    },
    {
      "@type": "Question",
      "name": "What are the essential incident response steps for mitigating a Gupd compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Gupd should immediately isolate affected endpoints from the network, perform memory triage to capture volatile forensic artifacts, audit registry and startup persistence mechanisms, revoke exposed user credentials, and restore systems from verified, clean backups."
      }
    },
    {
      "@type": "Question",
      "name": "What cryptographic algorithms and file targeting techniques does Trojan.Gupd employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Trojan.Gupd typically leverages hybrid cryptographic architectures combining symmetric stream or block ciphers (such as AES-256 or ChaCha20) for rapid file encryption with asymmetric algorithms (such as RSA-2048 or Curve25519) to securely protect the session keys. It aggressively targets sensitive file extensions including corporate documents, databases, virtual disks, and backups while systematically executing commands to delete Volume Shadow Copies (vssadmin delete shadows /all /quiet) and disable system recovery options."
      }
    },
    {
      "@type": "Question",
      "name": "Are decryptors available for Trojan.Gupd, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for Trojan.Gupd depends on whether security researchers or law enforcement (such as the No More Ransom initiative) have recovered the master private keys or discovered flaws in its key generation routines. Victims should never pay the extortion demand, as payment fuels criminal operations without guaranteeing file restoration. The recommended recovery procedure entails isolating infected hosts, conducting forensic disk imaging, identifying the root access vector, and restoring validated systems from immutable offline backups."
      }
    }
  ],
  "faq_count": 5,
  "mitre_attack": [
    "T1036.005",
    "T1053.005",
    "T1105"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-10-15",
  "type": "Trojan (Fake Update)",
  "target_industries": [
    "Healthcare",
    "Critical Infrastructure",
    "Enterprise"
  ],
  "motivation": "Financial Extortion",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ],
  "attack_stage": [
    "defense_evasion",
    "impact"
  ],
  "ecosystem": [
    "windows_pe"
  ],
  "is_emerging": false,
  "mitre_attack_detail": [
    {
      "id": "T1036.005",
      "name": "Match Legitimate Name or Location",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1053.005",
      "name": "Scheduled Task/Job: Scheduled Task (Using tasks for persistent, recurring execution)",
      "tactic": "Persistence"
    },
    {
      "id": "T1105",
      "name": "Ingress Tool Transfer",
      "tactic": "Command and Control"
    }
  ],
  "containment_steps": [
    "Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Gupd from spreading laterally or encrypting network-attached storage (NAS) and shared SMB volumes.",
    "Preserve volatile system memory (RAM capture) on a representative endpoint before attempting a reboot or power-down, as Gupd symmetric encryption keys or uncompiled payload components may still reside in memory.",
    "Audit process execution logs and terminate active scripting interpreters (e.g. PowerShell, CMD, WScript) or commands executing 'vssadmin.exe delete shadows' or 'wbadmin' used by Gupd to inhibit recovery.",
    "Investigate the initial compromise vector (such as exposed RDP instances, spearphishing attachments, or vulnerable edge gateways) and enforce an immediate credential reset for all compromised Active Directory accounts.",
    "Restore critical assets and databases exclusively from verified, air-gapped, or immutable offline backups once the Gupd binary and related persistence hooks are eradicated."
  ],
  "what_to_avoid": [
    "Do not restart or power cycle infected systems prematurely; doing so destroys volatile RAM encryption keys and may trigger bootloader locking logic embedded in Gupd.",
    "Avoid negotiating or paying the extortion demand without prior forensic evaluation and consultation with incident response specialists, as payment does not guarantee data recovery.",
    "Do not connect clean backup drives or external storage to the affected network until Gupd eradication is completely verified."
  ],
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}