{
  "family": "esaprof",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nEsaprof is a prevalent family of Adware and Potentially Unwanted Programs (PUPs) engineered to aggressively monetize an infected user's web browsing activity. It operates by altering browser configurations, injecting intrusive advertisements into web traffic, and covertly tracking user behavior, leading to significant degradation in system performance and user privacy.\n\n<h3>Distribution and Technical Behavior</h3>\nEsaprof is almost exclusively distributed via deceptive software bundling. Users inadvertently infect their systems when downloading \"free\" software from third-party download portals, where Esaprof is silently installed in the background via pre-checked installation options.\n\nOnce active, Esaprof deeply integrates with installed web browsers (Google Chrome, Firefox, Edge). Its core behaviors include:\n<ul>\n<li><strong>Browser Hijacking:</strong> Forcibly altering the default search engine, homepage, and new tab settings to redirect all traffic through an affiliate-linked search portal controlled by the adware operators.</li>\n<li><strong>Traffic Interception and Injection:</strong> Esaprof frequently installs a local proxy server or malicious browser extensions to intercept unencrypted web traffic, overlaying legitimate websites with intrusive pop-ups, pop-unders, banner ads, and sponsored in-text hyperlinks.</li>\n<li><strong>Data Harvesting:</strong> Continuously tracking the user's browsing history, search queries, and clickstreams to serve highly targeted advertisements and to sell this telemetry to data brokers.</li>\n</ul>\n\n<h3>Risk Assessment</h3>\nWhile Esaprof does not encrypt files or act as a remote access trojan, it introduces significant operational friction and risk. The injected advertisements are frequently served by low-reputation ad networks, dramatically increasing the likelihood of \"malvertising\" attacks that can lead to severe secondary infections, such as ransomware.\n\n<h3>Mitigation and Removal Strategies</h3>\n<ul>\n<li><strong>Browser Remediation:</strong> Manually inspect and remove any unknown or unauthorized extensions from all installed web browsers. Perform a complete factory reset of the browsers to clear hijacked search and homepage configurations.</li>\n<li><strong>Endpoint Scanning:</strong> Utilize a reputable enterprise-grade anti-malware solution to perform a deep system scan, targeting the Esaprof executables, hidden scheduled tasks, and persistent registry keys.</li>\n<li><strong>Application Control:</strong> Enforce strict application whitelisting policies to prevent standard users from executing unapproved software installers that frequently bundle adware.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Adware.Esaprof",
    "PUP.Esaprof",
    "BrowserModifier.Esaprof"
  ],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Esaprof and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Esaprof 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 Esaprof establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Esaprof 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 Esaprof compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Esaprof 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 Adware.Esaprof employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Adware.Esaprof 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 Adware.Esaprof, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for Adware.Esaprof 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": [
    "T1566.002",
    "T1176",
    "T1112"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-10-15",
  "type": "Adware",
  "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": "T1566.002",
      "name": "Phishing: Spearphishing Link (Social engineering to force the user to download the tool)",
      "tactic": "Initial Access"
    },
    {
      "id": "T1176",
      "name": "Browser Extensions",
      "tactic": "Persistence"
    },
    {
      "id": "T1112",
      "name": "Modify Registry",
      "tactic": "Defense Evasion"
    }
  ],
  "containment_steps": [
    "Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Esaprof 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 Esaprof 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 Esaprof 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 Esaprof 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 Esaprof.",
    "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 Esaprof eradication is completely verified."
  ],
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}