{
  "family": "multiminer",
  "sample_count": 3,
  "category": "ransomware",
  "description": "CoinMiner:Win32/Multiminer represents a prevalent class of malware known as **Cryptojackers or Cryptocurrency Miners**. Unlike ransomware that destroys data, Multiminer's objective is entirely parasitic: it silently hijacks the infected computer's processing power (CPU and/or GPU) to solve complex cryptographic algorithms, mining cryptocurrency (like Monero or Bitcoin) and sending the profits directly to the attacker's wallet.<br><br><b>Understanding Multiminer (Cryptojacking)</b><br>To an end-user, the primary symptom of a Multiminer infection is severe system sluggishness. The computer's fans will spin constantly at maximum speed, applications will hang, and laptop batteries will drain rapidly. For an enterprise, widespread cryptomining infections represent a massive, unauthorized consumption of electricity and cloud computing resources, resulting in tangible financial loss and hardware degradation.<br><br><b>Execution and Resource Hijacking Mechanics</b><br>Multiminer is often distributed via opportunistic botnets scanning for unpatched vulnerabilities (like EternalBlue), malicious email attachments (`T1566.001`), or bundled with pirated software. Upon execution, it establishes persistence, often running as a hidden Windows Service (`T1543.003`) or via a scheduled task. The core payload (`T1496`) is a mining binary (often a modified version of open-source tools like XMRig). The malware configures the miner to connect to a specific mining pool over the internet (`T1071.001`), providing the attacker's wallet address. Advanced variants use defense evasion techniques to detect if Task Manager or security tools are opened, temporarily pausing the mining process to avoid detection (`T1562.001`).<br><br><b>Indicators of Compromise & Impact</b><br>The impact is significant resource theft, hardware wear, and inflated cloud infrastructure bills. Host-based IoCs include EDR alerts for sustained, 100% CPU/GPU utilization by unknown processes (often disguised as `svchost.exe` or `wuauclt.exe`). Network IoCs are highly distinct: consistent, unencrypted TCP connections to known cryptocurrency mining pools (e.g., using the Stratum protocol on ports 3333, 14444, or 443).",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Multiminer and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Multiminer 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 Multiminer establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Multiminer 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 Multiminer compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Multiminer 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 Multiminer employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Multiminer 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 Multiminer, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for Multiminer 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": [
    "T1071.001",
    "T1496",
    "T1543.003",
    "T1562.001"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1496",
      "name": "Resource Hijacking (Cryptocurrency mining)",
      "tactic": "Impact"
    },
    {
      "id": "T1071.001",
      "name": "Application Layer Protocol: Web Protocols (Connecting to mining pools)",
      "tactic": "Command and Control"
    },
    {
      "id": "T1543.003",
      "name": "Create or Modify System Process: Windows Service",
      "tactic": "Persistence"
    },
    {
      "id": "T1562.001",
      "name": "Impair Defenses: Disable or Modify Tools (Pausing mining when Task Manager opens)",
      "tactic": "Defense Evasion"
    }
  ],
  "containment_steps": [
    "Isolate the endpoint to immediately sever the connection to the mining pool and halt the unauthorized resource consumption.",
    "Use EDR or Process Explorer to identify the heavily obfuscated mining process consuming CPU cycles and terminate it.",
    "Audit Windows Services and Scheduled Tasks to locate and remove the persistence mechanisms used to restart the miner.",
    "Implement network-level blocking of known cryptocurrency mining pool IP addresses and domains at the corporate firewall."
  ],
  "what_to_avoid": [
    "Do not ignore complaints of 'slow computers'; while often a benign IT issue, widespread sluggishness is a primary indicator of a cryptojacking outbreak.",
    "Avoid assuming cryptominers are harmless; threat actors often deploy miners as a secondary payload after establishing a backdoor, meaning data theft may have also occurred."
  ],
  "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,
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}