{ "family": "webdial", "sample_count": 1, "category": "advanced_threat", "description": "

Executive Summary

\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

Infection Vector and Technical Capabilities

\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\n\n

Threat Assessment

\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

Historical Remediation

\n", "cta": "Published by the SystemHelpdesk team.", "aliases": [ "Dialer.Webdial", "Trojan.Dialer", "Win32/Dialer" ], "enrichment_level": "expert-seo", "faq": [ { "@type": "Question", "name": "What is Webdial and what threat category does it belong to?", "acceptedAnswer": { "@type": "Answer", "text": "Webdial is classified as a Advanced Threat. 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 Webdial establish persistence and evade defensive controls?", "acceptedAnswer": { "@type": "Answer", "text": "Webdial 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 Webdial compromise?", "acceptedAnswer": { "@type": "Answer", "text": "Security teams responding to Webdial 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 lateral movement and credential access tactics does Dialer.Webdial leverage in enterprise intrusions?", "acceptedAnswer": { "@type": "Answer", "text": "Dialer.Webdial frequently utilizes privileged account harvesting techniques such as LSASS memory dumping, Kerberoasting, and token impersonation to escalate privileges. Once administrative credentials are acquired, it pivots across the victim network utilizing living-off-the-land binaries (LOLBins) such as WMI, PowerShell remoting, and PsExec, or abuses remote desktop protocols (RDP) to reach critical internal repositories and domain controllers." } }, { "@type": "Question", "name": "How does Dialer.Webdial maintain covert communications and evade perimeter network monitoring?", "acceptedAnswer": { "@type": "Answer", "text": "Dialer.Webdial often relies on multi-stage command and control (C2) architectures utilizing encrypted protocols over standard web ports (HTTPS/443 or DNS tunneling) to blend in with legitimate enterprise network traffic. Many variants incorporate proxy networks, domain fronting, or cloud services (such as Microsoft Graph API, Google Drive, or Telegram) to masquerade C2 channels, bypassing traditional signature-based egress filtering." } } ], "faq_count": 5, "mitre_attack": [ "T1499", "T1132", "T1059.001", "T1055", "T1071.001", "T1027" ], "cisa_advisory": null, "last_updated": "2026-10-15", "type": "Dialer (Legacy)", "target_industries": [ "Global / Opportunistic" ], "motivation": "Opportunistic", "threat_actors": [ "Unknown / Cybercriminal" ], "target_geographies": [ "Global" ], "attack_stage": [ "execution", "persistence" ], "ecosystem": [ "windows_pe" ], "is_emerging": false, "mitre_attack_detail": [ { "id": "T1499", "name": "Endpoint Denial of Service (Consuming resources via invisible ad loading and click fraud)", "tactic": "Impact" }, { "id": "T1132", "name": "Data Encoding", "tactic": "Command and Control" }, { "id": "T1059.001", "name": "Command and Scripting Interpreter: PowerShell (Used in infection chain)", "tactic": "Execution" }, { "id": "T1055", "name": "Process Injection", "tactic": "Defense Evasion" }, { "id": "T1071.001", "name": "Application Layer Protocol: Web Protocols (C2 Communication)", "tactic": "Command and Control" }, { "id": "T1027", "name": "Obfuscated Files or Information", "tactic": "Defense Evasion" } ], "containment_steps": [ "Enforce forensic network isolation on all suspected endpoints while maintaining an out-of-band telemetry conduit to capture live Webdial adversary activity.", "Perform full memory dumps across identified staging nodes to extract memory-only implants, kernel rootkit hooks, and decrypted Webdial C2 infrastructure IP/domain lists.", "Review Active Directory domain controller authentication logs for anomalous Kerberos ticket requests (Pass-the-Ticket, Golden Ticket) and unauthorized DCSync operations associated with Webdial.", "Block all confirmed C2 domains, dynamic DNS endpoints, and proxy IP addresses across perimeter firewalls, proxies, and DNS security gateways.", "Conduct an enterprise-wide sweep across surrounding subnets for secondary webshells, WMI event subscriptions, or remote execution tooling left behind by Webdial operators." ], "what_to_avoid": [ "Do not assume the incident is resolved simply because an antivirus tool removed the initial Webdial dropper; always verify that secondary payloads and persistence hooks have been eradicated.", "Avoid logging in with Domain Admin or privileged credentials on a machine suspected of running Webdial until memory triage is complete.", "Do not delay host isolation; automated lateral movement and credential dumping can occur within minutes of initial execution." ], "target_platforms": [ "Windows 11", "Windows 10", "Windows Server 2022", "Windows Server 2019" ] }