{
  "family": "paper",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nThe \"Paper\" malware family is typically categorized as adware, a Potentially Unwanted Program (PUP), or a browser hijacker. It is engineered to aggressively monetize an infected user's web traffic by injecting unauthorized advertisements, modifying search engine results, and tracking browsing habits without transparent consent.\n\n<h3>Infection Vector and Operational Tactics</h3>\nPaper predominantly relies on software bundling for distribution. Users inadvertently install the adware when downloading \"free\" utilities—such as PDF converters, media players, or file extractors—from deceptive third-party software repositories. The adware components are hidden within \"Express\" or \"Recommended\" installation paths.\n\nUpon installation, Paper embeds itself deeply within the operating system and installed web browsers (Chrome, Edge, Firefox) via malicious extensions and modified proxy settings. Its primary behaviors include:\n<ul>\n<li><strong>Ad Injection:</strong> Overlaying intrusive banner ads, pop-ups, and in-text hyperlinks on legitimate websites, severely degrading the user experience.</li>\n<li><strong>Search Hijacking:</strong> Forcing the default search engine and homepage to redirect to an affiliate-controlled search portal, ensuring the adware operators receive a commission for every query.</li>\n<li><strong>Data Harvesting:</strong> Continuously tracking the user's browsing history, search terms, and location data to build profiles for targeted advertising or to sell to third-party data brokers.</li>\n</ul>\n\n<h3>Security and Privacy Risks</h3>\nWhile Paper does not typically exhibit destructive capabilities like ransomware, it poses a significant risk to user privacy and system stability. The injected advertisements are frequently served by low-reputation ad networks, increasing the likelihood of \"malvertising\" attacks that can lead to severe secondary infections.\n\n<h3>Mitigation and Removal</h3>\n<ul>\n<li><strong>Browser Remediation:</strong> Remove any unknown or suspicious browser extensions. Perform a complete reset of the affected web browsers to clear modified search and homepage settings.</li>\n<li><strong>Endpoint Scanning:</strong> Utilize a reputable anti-malware or EDR solution to scan for and remove the underlying executables and registry modifications associated with the Paper family.</li>\n<li><strong>Software Policies:</strong> Enforce strict application control policies (e.g., AppLocker) to prevent users from executing unapproved software installers that frequently bundle adware.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Adware.Paper",
    "PUP.Paper",
    "BrowserModifier.Paper"
  ],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Paper and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Paper 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 Paper establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Paper 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 Paper compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Paper 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.Paper employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Adware.Paper 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.Paper, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for Adware.Paper 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 Paper 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 Paper 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 Paper 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 Paper 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 Paper.",
    "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 Paper eradication is completely verified."
  ],
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}