{
  "family": "lsslogger",
  "sample_count": 4,
  "category": "trojan",
  "description": "Trojan:Win32/Lsslogger is a specialized, stealthy trojan designed exclusively for credential theft, specifically operating as a **Keylogger**. Unlike broad information stealers that simply scrape browser files, Lsslogger focuses on intercepting user input at the operating system level, capturing passwords, emails, and sensitive communications as they are typed, before they are encrypted by applications.<br><br><b>Understanding Lsslogger (Keyloggers)</b><br>To an end-user, Lsslogger is completely invisible; it does not display windows or impact performance. For a security analyst, a keylogger represents a severe breach of confidentiality. It implies that any credential entered on the compromised machine (including highly secure passwords not saved in browsers) is now in the hands of the attacker, often facilitating immediate lateral movement.<br><br><b>Execution and Interception Mechanics</b><br>Lsslogger is typically dropped by a primary infection vector, such as a malicious Office macro (`T1566.001`) or a downloader trojan. Once executed, it establishes persistence via the Registry Run keys or hidden scheduled tasks (`T1547.001`). Its core function relies on hooking Windows APIs (`T1056.001`). It uses functions like `SetWindowsHookEx` to intercept keyboard events before they reach the target application (like a web browser or VPN client). The captured keystrokes are recorded into a hidden, often encrypted, log file stored in the `%Temp%` or `System32` directory. Periodically, Lsslogger compresses this log file and exfiltrates it to the attacker, often using simple protocols like SMTP (emailing the logs to a disposable address) or FTP upload (`T1048.003`).<br><br><b>Indicators of Compromise & Impact</b><br>The impact is the total compromise of all accounts accessed from the infected machine. Host-based IoCs include EDR alerts for 'Suspicious API Hooking' targeting input functions, and the presence of rapidly growing, encrypted `.dat` or `.log` files in user profile directories. Network IoCs often include anomalous outbound SMTP (port 25, 465, 587) or FTP (port 21) traffic originating from a standard Windows process rather than a legitimate email client.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Lsslogger and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Lsslogger 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 Lsslogger establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Lsslogger 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 Lsslogger compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Lsslogger 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 Lsslogger?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Lsslogger 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 Lsslogger across enterprise endpoints?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Defenders should hunt for Lsslogger 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",
    "T1056.001",
    "T1048.003",
    "T1547.001"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1056.001",
      "name": "Input Capture: Keylogging (API Hooking via SetWindowsHookEx)",
      "tactic": "Collection"
    },
    {
      "id": "T1055",
      "name": "Process Injection (Injecting hooks into other processes)",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1048.003",
      "name": "Exfiltration Over Alternative Protocol (Exfiltrating logs via SMTP/FTP)",
      "tactic": "Exfiltration"
    },
    {
      "id": "T1547.001",
      "name": "Boot or Logon Autostart Execution",
      "tactic": "Persistence"
    }
  ],
  "containment_steps": [
    "Assume ALL credentials typed on the machine (corporate passwords, personal banking, SSH keys) are compromised and force immediate resets from a known-clean device.",
    "Isolate the endpoint to stop the active exfiltration of the keylogger log files.",
    "Analyze the memory of running processes to identify the specific module performing the API hooking and extract its configuration (which will reveal the attacker's email/FTP drop zone).",
    "Review authentication logs across the network for the compromised user's credentials to detect if the attacker has already used the stolen passwords for lateral movement."
  ],
  "what_to_avoid": [
    "Do not assume multi-factor authentication (MFA) provides complete protection; while it helps, a keylogger will capture the username and password, giving the attacker half of what they need.",
    "Avoid relying solely on file deletion; advanced keyloggers often inject their hooking DLLs into legitimate processes like `explorer.exe`, requiring a reboot or process termination to fully unload."
  ],
  "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"
  ]
}