{
  "family": "informer",
  "sample_count": 8,
  "category": "trojan",
  "description": "Spyware:Win32/Informer is a persistent, stealthy spyware and keylogger designed to breach endpoint defenses and securely collect, log, and exfiltrate highly sensitive user activity, including keystrokes, screenshots, and clipboard data, to a remote attacker.<br><br><b>Understanding Informer Spyware</b><br>To an end-user, an Informer infection is entirely invisible. The software operates deep in the background, specifically designed to hide from the Task Manager and system tray. For a security analyst, discovering Informer on a corporate endpoint indicates a critical breach of privacy and a highly likely compromise of all credentials and sensitive communications entered on that machine.<br><br><b>Execution and Surveillance Mechanics</b><br>Informer is typically installed via spearphishing (`T1566.001`) bundled with an exploit or dropped by a primary trojan. Once executed (`T1204.002`), it establishes deep persistence, often by creating a hidden Windows Service (`T1543.003`) or manipulating the Registry Run keys (`T1547.001`). Its primary function is collection: it utilizes Windows API hooks (like `SetWindowsHookEx`) to log every keystroke (`T1056.001`), takes periodic hidden screenshots of the desktop (`T1113`), and captures clipboard data (`T1115`). The harvested data is then encrypted and silently emailed to the attacker or uploaded to a remote FTP server (`T1041`).<br><br><b>Indicators of Compromise & Impact</b><br>The primary impact is the catastrophic loss of confidentiality and credential compromise. EDR logs are critical for detecting this threat, specifically looking for processes injecting into `explorer.exe` or hooking the keyboard APIs. Network analysts should look for unauthorized, recurring outbound SMTP (email) or FTP traffic originating from the endpoint. Host-based IoCs include the presence of hidden, encrypted log files (often with extensions like `.dat` or `.log`) buried deeply in the `%AppData%` or `%ProgramData%` directories.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Informer and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Informer 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 Informer establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Informer 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 Informer compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Informer 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 Informer?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Informer 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 Informer across enterprise endpoints?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Defenders should hunt for Informer 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": [
    "T1056.001",
    "T1115",
    "T1048.003",
    "T1113"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1056.001",
      "name": "Input Capture: Keylogging",
      "tactic": "Collection"
    },
    {
      "id": "T1113",
      "name": "Screen Capture",
      "tactic": "Collection"
    },
    {
      "id": "T1115",
      "name": "Clipboard Data",
      "tactic": "Collection"
    },
    {
      "id": "T1048.003",
      "name": "Exfiltration Over Alternative Protocol (Exfiltration via Email/FTP)",
      "tactic": "Exfiltration"
    }
  ],
  "containment_steps": [
    "Instantly isolate the endpoint to halt the exfiltration of the captured keystrokes and screenshots.",
    "Enforce a mandatory, immediate password reset for *every* account the user has accessed from that machine, prioritizing domain credentials and VPN access.",
    "Do not simply delete the executable; spyware often uses rootkit-like techniques to hide. Use an enterprise EDR solution to forcefully terminate the hooking service and clean the registry.",
    "Perform a forensic review to determine how the software was installed (checking for phishing vectors)."
  ],
  "what_to_avoid": [
    "Do not assume only the local user's data was compromised; if an administrator logged into the infected machine, their credentials were also logged.",
    "Avoid leaving the endpoint on the network while investigating, as the spyware will continue to transmit data in real-time."
  ],
  "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"
  ]
}