{ "family": "fantom", "sample_count": 1, "category": "ransomware", "description": "

Executive Summary

\nFantom is a highly deceptive Ransomware family that utilizes social engineering at the operating system level. It is designed to extort financial payment from victims by encrypting their critical data while masquerading as a legitimate, critical Windows Update. This visual deception keeps the user unaware of the ongoing encryption process until it is too late.\n\n

Infection Vector and Technical Capabilities

\nFantom is primarily distributed through deceptive software downloads, fake software updates on untrustworthy websites, or via malspam campaigns containing disguised executables.\n\nUpon execution, Fantom initiates a highly deceptive and destructive attack sequence:\n\n\n

Threat Assessment

\nA Fantom infection is a critical security incident resulting in immediate loss of data availability. The deceptive \"Windows Update\" overlay is highly effective against non-technical users, ensuring the encryption process completes uninterrupted. The destruction of local backups means organizations face massive data loss without offline contingencies.\n\n

Incident Response and Remediation

\n", "cta": "Published by the SystemHelpdesk team.", "aliases": [ "Ransom.Fantom", "Trojan-Ransom.Win32.Fantom", "Win32/Filecoder.Fantom" ], "enrichment_level": "expert-seo", "faq": [ { "@type": "Question", "name": "What is Fantom and what threat category does it belong to?", "acceptedAnswer": { "@type": "Answer", "text": "Fantom 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 Fantom establish persistence and evade defensive controls?", "acceptedAnswer": { "@type": "Answer", "text": "Fantom 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 Fantom compromise?", "acceptedAnswer": { "@type": "Answer", "text": "Security teams responding to Fantom 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 Ransom.Fantom employ during execution?", "acceptedAnswer": { "@type": "Answer", "text": "Ransom.Fantom 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 Ransom.Fantom, and what is the recommended recovery procedure?", "acceptedAnswer": { "@type": "Answer", "text": "Decryption availability for Ransom.Fantom 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": [ "T1486", "T1490", "T1036.003" ], "cisa_advisory": null, "last_updated": "2026-10-15", "type": "Ransomware / Scareware", "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": "T1486", "name": "Data Encrypted for Impact", "tactic": "Impact" }, { "id": "T1490", "name": "Inhibit System Recovery (Behaviorally blocking the deletion of backups)", "tactic": "Impact" }, { "id": "T1036.003", "name": "Masquerading: Rename System Utilities (Using folder icons for executables)", "tactic": "Defense Evasion" } ], "containment_steps": [ "Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Fantom 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 Fantom 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 Fantom 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 Fantom 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 Fantom.", "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 Fantom eradication is completely verified." ], "target_platforms": [ "Windows 11", "Windows 10", "Windows Server 2022", "Windows Server 2019" ] }