{
  "family": "e2f3f4d",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\n\"e2f3f4d\" (and similar purely hexadecimal strings) represents a strict, static hash-based detection signature utilized by antivirus engines. It does not identify a named malware family, but rather acts as a direct blocklist entry for a specific, known malicious file whose cryptographic hash (like MD5 or SHA-256) matches the identifier.\n\n<h3>Static Detection and Technical Context</h3>\nUnlike heuristic detections (which analyze behavior), a hash-based detection like \"e2f3f4d\" means the endpoint protection platform (EPP) has encountered a file that is an exact, byte-for-byte match with a piece of malware that has been previously analyzed and definitively classified as malicious by the security vendor.\n\nThe implications of a hash-based detection include:\n<ul>\n<li><strong>High Confidence:</strong> Hash detections have an extremely low false-positive rate. If a file triggers this alert, it is almost certainly malicious.</li>\n<li><strong>Lack of Context:</strong> While the detection is highly accurate, the identifier itself provides no context about what the malware actually does (e.g., whether it is an info-stealer, ransomware, or adware).</li>\n<li><strong>Evasion Vulnerability:</strong> Hash-based detections are easily bypassed by malware authors. Changing a single byte of the malicious executable (e.g., recompiling it or adding a null byte) completely alters the resulting hash, rendering the static signature useless.</li>\n</ul>\n\n<h3>Threat Impact and Response</h3>\nWhile the alert confirms the presence of known malware, responders must treat it as a critical indicator that perimeter defenses were bypassed. The primary concern is whether the file was blocked pre-execution or if the hash was only detected during a post-execution sweep.\n\n<h3>Incident Mitigation Strategy</h3>\n<ul>\n<li><strong>Verify Execution Status:</strong> Check the EDR logs immediately to determine if the EPP successfully blocked the file from executing, or if it was only flagged after the process was already running.</li>\n<li><strong>Hash Lookups:</strong> Take the full SHA-256 hash associated with the alert and query it against threat intelligence platforms (like VirusTotal) to identify the true malware family and obtain actionable context on its capabilities.</li>\n<li><strong>Endpoint Sweeps:</strong> Utilize the identified hash as an Indicator of Compromise (IOC) to sweep the entire enterprise network, ensuring the specific malicious file has not been dropped on other hosts.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Trojan.Hash",
    "Malware.e2f3f4d"
  ],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is E2F3F4D and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "E2F3F4D 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 E2F3F4D establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "E2F3F4D 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 E2F3F4D compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to E2F3F4D 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.Hash employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Trojan.Hash 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.Hash, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for Trojan.Hash 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",
    "T1082",
    "T1027"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-10-15",
  "type": "Generic",
  "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": "T1082",
      "name": "System Information Discovery",
      "tactic": "Discovery"
    },
    {
      "id": "T1027",
      "name": "Obfuscated Files or Information",
      "tactic": "Defense Evasion"
    }
  ],
  "containment_steps": [
    "Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent E2F3F4D 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 E2F3F4D 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 E2F3F4D 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 E2F3F4D 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 E2F3F4D.",
    "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 E2F3F4D eradication is completely verified."
  ],
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}