{
  "family": "coinloader",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nCoinloader is a specialized Trojan Downloader engineered with a singular, primary objective: to silently infect a system and subsequently download, install, and execute unauthorized cryptocurrency mining software (Cryptojacking). The malware hijacks the victim's CPU and GPU processing power to generate digital currency (typically Monero) for the threat actors.\n\n<h3>Infection Vector and Technical Capabilities</h3>\nCoinloader is widely distributed via \"fileless\" attacks (such as exploiting vulnerabilities in unpatched web servers or databases like Redis/MSSQL), malicious email attachments, or hidden within pirated software and game torrents.\n\nOnce executed on a host, Coinloader operates with a focus on resource hijacking:\n<ul>\n<li><strong>Miner Deployment:</strong> The downloader reaches out to attacker-controlled infrastructure (often utilizing paste sites like Pastebin or compromised GitHub repositories) to download an open-source or custom-built mining application (e.g., XMRig).</li>\n<li><strong>Stealth and Evasion:</strong> To prevent the user from noticing the massive spike in CPU usage, the loader often injects the miner into a legitimate Windows process (`svchost.exe`, `notepad.exe`). Advanced variants will actively monitor the Task Manager; if the user opens the Task Manager, the miner temporarily suspends its activity to hide the CPU spike.</li>\n<li><strong>Defense Evasion:</strong> Coinloader frequently utilizes PowerShell scripts to modify Windows Defender settings, adding exclusions for its own directories to prevent the miner from being quarantined.</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nWhile Coinloader does not typically steal data or encrypt files like ransomware, it causes massive disruption. The constant 100% CPU/GPU utilization renders the workstation or server practically unusable, causes severe physical overheating (potentially damaging hardware), and significantly inflates corporate electricity and cloud computing costs.\n\n<h3>Incident Response and Remediation</h3>\n<ul>\n<li><strong>Network Isolation and Process Termination:</strong> Identify the process consuming massive CPU resources (often a legitimate-sounding process name running from an unusual directory like `%AppData%`). Terminate the process and isolate the machine to halt mining and prevent re-infection.</li>\n<li><strong>Hunting for Persistence:</strong> Coinloader relies heavily on Scheduled Tasks and WMI (Windows Management Instrumentation) event subscriptions for persistence. Thoroughly audit these areas using PowerShell or EDR tools.</li>\n<li><strong>Review AV Exclusions:</strong> Carefully review the local Antivirus/Windows Defender settings. The malware likely added folder or process exclusions that must be manually removed before a clean scan can be performed.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Trojan.Downloader.CoinMiner",
    "Riskware.Coinloader",
    "CoinMiner"
  ],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Coinloader and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Coinloader 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 Coinloader establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Coinloader 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 Coinloader compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Coinloader 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.Downloader.CoinMiner employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Trojan.Downloader.CoinMiner 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.Downloader.CoinMiner, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for Trojan.Downloader.CoinMiner 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": [
    "T1105",
    "T1496",
    "T1562.001",
    "T1055"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-10-15",
  "type": "Downloader / Cryptominer",
  "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": "T1105",
      "name": "Ingress Tool Transfer",
      "tactic": "Command and Control"
    },
    {
      "id": "T1496",
      "name": "Resource Hijacking (The core function of mining Monero cryptocurrency)",
      "tactic": "Impact"
    },
    {
      "id": "T1562.001",
      "name": "Impair Defenses: Disable or Modify Tools",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1055",
      "name": "Process Injection",
      "tactic": "Defense Evasion"
    }
  ],
  "containment_steps": [
    "Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Coinloader 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 Coinloader 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 Coinloader 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 Coinloader 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 Coinloader.",
    "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 Coinloader eradication is completely verified."
  ],
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}