{
  "family": "webdial",
  "sample_count": 1,
  "category": "advanced_threat",
  "description": "<h3>Executive Summary</h3>\nWebdial is a classic example of legacy malware classified as a \"Dialer.\" Highly prevalent during the era of dial-up internet access, Dialers were designed to hijack a computer's modem. Without the user's consent or knowledge, they would disconnect the active internet connection and automatically silently dial an expensive, international, or premium-rate toll number controlled by the attackers, resulting in massive, unexpected telephone bills for the victim.\n\n<h3>Infection Vector and Technical Capabilities</h3>\nWebdial was frequently distributed via deceptive websites (often adult content or \"free software\" portals). Users would be prompted to download a \"special access viewer\" or a required \"codec\" to view the site's content, which was actually the malicious dialer executable.\n\nUpon execution, the Dialer operated through direct hardware manipulation:\n<ul>\n<li><strong>Modem Hijacking:</strong> The malware altered the Windows Dial-Up Networking (DUN) configurations. It suppressed the modem's speaker volume (to prevent the user from hearing the dialing tones) and changed the default dial-up connection number.</li>\n<li><strong>Toll Fraud:</strong> The dialer would forcefully disconnect the user's local ISP and redial a premium-rate number (often starting with 1-900 or international country codes). The operators of the malware received a cut of the exorbitant per-minute charges levied by the telephone company.</li>\n<li><strong>Persistence:</strong> Webdial often placed shortcuts in the Windows Startup folder and modified Registry Run keys to ensure it re-dialed the premium number every time the computer booted.</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nIn modern enterprise and consumer environments that utilize broadband (Cable, Fiber, DSL), Webdial and other traditional dialers are entirely obsolete and physically incapable of functioning, as broadband connections do not \"dial\" phone numbers over analog lines. However, they remain a historically significant example of early financially motivated cybercrime.\n\n<h3>Historical Remediation</h3>\n<ul>\n<li><strong>Connection Termination:</strong> The immediate response required physically unplugging the telephone line from the computer's modem to halt the expensive call.</li>\n<li><strong>DUN Reconfiguration:</strong> Remediation involved removing the malicious executable and manually reviewing and deleting the unauthorized connections created within the Windows Dial-Up Networking control panel.</li>\n<li><strong>Financial Dispute:</strong> Victims often had to undergo a lengthy dispute process with their local telephone provider to have the fraudulent, premium-rate charges removed from their monthly bills.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Dialer.Webdial",
    "Trojan.Dialer",
    "Win32/Dialer"
  ],
  "enrichment_level": "insufficient_information",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1499",
    "T1132"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-07-01T17:20:25Z",
  "type": "Dialer (Legacy)",
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}