{
  "family": "egroupdial",
  "sample_count": 7,
  "category": "advanced_threat",
  "description": "Dialer:Win32/Egroupdial represents a legacy classification of malware that was highly prevalent during the era of dial-up internet modems. It is designed to commit financial fraud by silently disconnecting a user's modem from their standard Internet Service Provider (ISP) and reconnecting it to a premium-rate international or adult-service phone number, generating massive, unauthorized charges on the victim's phone bill.<br><br><b>Understanding Dialer Malware</b><br>To an end-user in the early 2000s, an Egroupdial infection was often unnoticeable until they received a phone bill for thousands of dollars in international calls. While modern broadband (cable/fiber) is entirely immune to dialers because they do not use phone lines to route traffic, Dialers remain a critical historical case study in automated financial extortion and telecommunications fraud.<br><br><b>Execution and Dialing Mechanics</b><br>Egroupdial was typically distributed via deceptive 'free access' links on adult websites or bundled with pirated software (`T1189`). Upon execution (`T1204.002`), the malware establishes persistence and immediately interfaces with the Windows Telephony Application Programming Interface (TAPI) (`T1562.001`). It suppresses the modem speaker volume so the user cannot hear the dialing tones (`T1562.001`). It then terminates the active dial-up connection and initiates a new PPP (Point-to-Point Protocol) connection to a hardcoded, premium-rate phone number controlled by the malware authors (`T1498`), keeping the connection open as long as possible to maximize revenue.<br><br><b>Indicators of Compromise & Impact</b><br>The primary impact is direct, massive financial loss for the user via their telecommunications provider. Technical IoCs on legacy systems included the creation of new, unauthorized Dial-Up Networking (DUN) profiles in the Windows Network Connections panel. Behavioral IoCs included the modem spontaneously disconnecting and reconnecting, and the modem speaker being permanently muted.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Egroupdial and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Egroupdial 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 Egroupdial establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Egroupdial 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 Egroupdial compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Egroupdial 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 Egroupdial leverage in enterprise intrusions?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Egroupdial 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 Egroupdial maintain covert communications and evade perimeter network monitoring?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Egroupdial 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": [
    "T1204.002",
    "T1189",
    "T1498",
    "T1562.001"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1498",
      "name": "Network Denial of Service (Legacy dialing fraud classification)",
      "tactic": "Impact"
    },
    {
      "id": "T1562.001",
      "name": "Impair Defenses: Disable or Modify Tools (Muting modem speakers to hide dialing)",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1189",
      "name": "Drive-by Compromise",
      "tactic": "Initial Access"
    },
    {
      "id": "T1204.002",
      "name": "User Execution: Malicious File",
      "tactic": "Execution"
    }
  ],
  "containment_steps": [
    "If analyzing a legacy system, physically unplug the phone line from the modem immediately to halt the fraudulent charges.",
    "Delete any unknown Dial-Up Networking (DUN) connection profiles found in the Network Connections control panel.",
    "Use standard antivirus to remove the Egroupdial executable and its persistence mechanisms.",
    "Contact the telecommunications provider to report the fraud and request a block on all international or premium-rate dialing from that landline."
  ],
  "what_to_avoid": [
    "Do not assume modern endpoints are vulnerable; this threat requires a physical analog modem connected to a landline to function.",
    "Avoid paying the phone bill without first disputing the charges as fraud with the telecommunications carrier."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ],
  "attack_stage": [
    "execution",
    "persistence"
  ],
  "ecosystem": [
    "windows_pe"
  ],
  "is_emerging": false,
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}