{
  "family": "virledi",
  "sample_count": 7,
  "category": "trojan",
  "description": "Virus:Win32/Virledi is a destructive and parasitic **File Infector**. Unlike standard trojans which simply run alongside legitimate programs, Virledi actively searches for executable files (such as `.exe`, `.dll`, or `.scr`) on the compromised system and physically alters them, injecting its own malicious code into the host file. This makes remediation significantly more complex than simply deleting a single dropped file.<br><br><b>Understanding File Infectors (Viruses)</b><br>To an end-user, the system may become unstable, applications might crash frequently, or antivirus software might suddenly start detecting hundreds of files as malicious. For a security analyst, a Virledi infection is a severe incident. Because it alters legitimate system files, manually deleting the 'infected' files will destroy the operating system or the user's installed applications. The malware must be carefully 'disinfected' (the malicious code surgically removed from the host file) to restore functionality.<br><br><b>Execution and Infection Mechanics</b><br>Virledi typically arrives via infected removable media, network shares, or downloaded as a payload from another trojan. Upon execution (`T1204.002`), it establishes persistence (`T1547.001`). Its primary routine involves traversing the file system (`T1083`). When it finds a target executable, it opens the file, modifies the PE (Portable Executable) header (`T1055.001`), and appends its malicious code—usually to a new section or the end of the file. It then alters the entry point of the executable to point to the viral code. When the user later runs the 'infected' legitimate application (e.g., `calc.exe` or a game), the virus code executes first, infects more files, and then passes control back to the legitimate application, often hiding the infection from the user.<br><br><b>Indicators of Compromise & Impact</b><br>The primary impact is the widespread corruption of executable files and severe system instability. The most glaring IoC is an avalanche of EDR alerts indicating that hundreds of distinct, legitimate executables across the `C:\\` drive are suddenly exhibiting malicious behavior or have changed their file hashes. File sizes of infected executables will be larger than their clean counterparts.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Virledi and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Virledi is classified as a Trojan. 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 Virledi establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Virledi 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 Virledi compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Virledi 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 secondary payloads and staging behaviors are commonly associated with Virledi?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Virledi frequently operates as a loader or dropper designed to establish a foothold before downloading and executing secondary high-impact malware payloads. Depending on the threat actor's objectives, these dropped modules can range from ransomware and banking injects to modular infostealers and remote management backdoors."
      }
    },
    {
      "@type": "Question",
      "name": "How can security operations teams effectively detect and hunt for Virledi across enterprise endpoints?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Defenders should hunt for Virledi by deploying behavioral endpoint detection and response (EDR) rules that monitor suspicious process spawning (such as cmd.exe or powershell.exe spawned from office documents or temporary directories), anomalous outbound network connections from non-browser binaries, and unauthorized modifications to Windows Run keys and scheduled task registries."
      }
    }
  ],
  "faq_count": 5,
  "mitre_attack": [
    "T1055.001",
    "T1204.002",
    "T1083",
    "T1547.001"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1055.001",
      "name": "Process Injection: Dynamic-link Library Injection (File Infection logic)",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1083",
      "name": "File and Directory Discovery (Searching for files to infect)",
      "tactic": "Discovery"
    },
    {
      "id": "T1547.001",
      "name": "Boot or Logon Autostart Execution: Registry Run Keys",
      "tactic": "Persistence"
    },
    {
      "id": "T1204.002",
      "name": "User Execution: Malicious File",
      "tactic": "Execution"
    }
  ],
  "containment_steps": [
    "Isolate the endpoint immediately to prevent the virus from spreading to mapped network drives or removable USB media.",
    "Do NOT attempt to manually delete infected files; this will likely destroy the operating system.",
    "Deploy an enterprise-grade antivirus solution capable of deep 'cleaning' or 'disinfection'—the process of stripping the viral code while repairing the original PE header.",
    "If disinfection fails or the system is too heavily corrupted, a complete wipe and OS rebuild from secure backups is the only safe remediation."
  ],
  "what_to_avoid": [
    "Avoid executing any files from the infected system on a clean system, even standard utilities, as they are likely infected carriers.",
    "Do not trust backups taken recently; file infectors often lay dormant, meaning your recent backups may contain infected executables."
  ],
  "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 7"
  ]
}