{
  "family": "blackstealer",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nBlackStealer is a malicious Information Stealer (Info Stealer) Trojan designed to covertly exfiltrate sensitive data from compromised Windows systems. Unlike large botnets, BlackStealer functions as a precision data-harvesting tool, specifically targeting login credentials, cryptocurrency wallets, financial data, and session tokens to facilitate immediate financial fraud or to sell the stolen access to Initial Access Brokers (IABs).\n\n<h3>Infection Vector and Technical Capabilities</h3>\nBlackStealer is typically distributed via spear-phishing campaigns (often disguised as invoices or shipping documents), bundled with cracked software on peer-to-peer networks, or deployed as a secondary payload by exploit kits.\n\nOnce executed, BlackStealer operates silently to harvest data:\n<ul>\n<li><strong>Credential Store Extraction:</strong> The primary function is the systematic extraction of saved passwords, cookies, and autofill data from the local databases of major web browsers (Chrome, Firefox, Edge, Opera).</li>\n<li><strong>Application Targeting:</strong> It specifically targets the configuration files and local storage of desktop email clients (Outlook, Thunderbird), FTP clients (FileZilla), and messaging applications (Discord, Telegram) to steal authentication tokens.</li>\n<li><strong>Cryptocurrency Wallet Theft:</strong> BlackStealer aggressively scans the file system for `wallet.dat` files and extensions associated with popular cryptocurrency wallets (Bitcoin Core, Electrum, Exodus).</li>\n<li><strong>Data Exfiltration:</strong> The harvested data is compressed into an archive (often a ZIP file) and rapidly exfiltrated to the attacker's Command and Control (C2) server via HTTP/HTTPS POST requests or Telegram bots.</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nA BlackStealer infection is a critical security incident that immediately compromises user identity and access. The theft of corporate VPN/RDP credentials or session cookies allows attackers to bypass perimeter security, including Multi-Factor Authentication (MFA), potentially leading to a massive enterprise data breach or ransomware deployment.\n\n<h3>Incident Response and Remediation</h3>\n<ul>\n<li><strong>Immediate Endpoint Isolation:</strong> The highest priority is to disconnect the infected endpoint from the network to halt the active exfiltration of the data archive.</li>\n<li><strong>Global Credential and Session Reset:</strong> It must be assumed that all passwords and session tokens present on the machine have been stolen. A mandatory, immediate reset of all associated credentials, and the revoking of all active web sessions, is absolutely required.</li>\n<li><strong>Complete Re-imaging:</strong> To ensure no hidden persistence mechanisms or secondary backdoors remain, the compromised endpoint must undergo a complete bare-metal wipe and re-image from a trusted baseline.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Trojan.BlackStealer",
    "Infostealer.Black",
    "Win32/Spy.Stealer"
  ],
  "enrichment_level": "insufficient_information",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1555.003",
    "T1005",
    "T1114"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-07-02T07:10:57Z",
  "type": "Trojan / Info Stealer",
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}