{
  "family": "fakecoder",
  "sample_count": 1,
  "category": "ransomware",
  "description": "Trojan:Win32/Fakecoder is a classic but enduring social engineering lure designed to trick users into executing malware under the guise of a required media player update. Attackers set up malicious streaming sites or seed torrents with video files that prompt the user to download a 'special codec' or 'video player update' to view the content. The downloaded file is, in fact, a trojan dropper (`T1204.002`).<br><br><b>Understanding Fakecoder (Social Engineering Delivery)</b><br>To an end-user, they are simply trying to watch a pirated movie, a sports stream, or adult content, and believe the prompt to update their software is legitimate. For a security team, a Fakecoder detection highlights a failure in user awareness training and a reliance on risky browsing behavior, providing a direct path for attackers to bypass email filters and network perimeters.<br><br><b>Execution and Delivery Mechanics</b><br>The attack relies heavily on user interaction. The victim navigates to a compromised site. The site uses JavaScript to detect the browser and serve a fake, highly realistic prompt (e.g., 'Flash Player is out of date' or 'Missing DivX Codec'). The user downloads the executable (often named `setup.exe` or `codec_pack.exe`) and runs it (`T1204.002`). The executable may actually install a basic media player to avoid suspicion, but silently drops a RAT, Adware, or Ransomware payload in the background (`T1027.002`).<br><br><b>Indicators of Compromise & Impact</b><br>The impact depends on the secondary payload delivered by the fake codec. Host-based IoCs include the execution of unsigned executables from the `%Downloads%` folder immediately following web browsing activity to high-risk sites (streaming, torrents). EDR will flag the 'codec' installer spawning unexpected child processes (like `cmd.exe` or `powershell.exe`) to establish persistence or reach out to a C2 server.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1027.002",
    "T1204.002",
    "T1189"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1204.002",
      "name": "User Execution: Malicious File (The core of the attack relies on tricking the user into running the file)",
      "tactic": "Execution"
    },
    {
      "id": "T1189",
      "name": "Drive-by Compromise (The malicious sites used to serve the fake prompts)",
      "tactic": "Initial Access"
    },
    {
      "id": "T1027.002",
      "name": "Obfuscated Files or Information: Software Packing (Hiding the malware inside the fake installer)",
      "tactic": "Defense Evasion"
    }
  ],
  "containment_steps": [
    "Isolate the machine; the fake codec was likely a dropper for a more severe payload (like an InfoStealer).",
    "Review web proxy logs for the infected host to identify the malicious streaming or download site, and block it enterprise-wide.",
    "Determine what the secondary payload was by analyzing the EDR process tree spawned by the downloaded executable.",
    "Conduct targeted security awareness training focusing on the dangers of pirated media and fake update prompts."
  ],
  "what_to_avoid": [
    "Do not close the incident just because the AV blocked the initial download; the user's risky browsing behavior needs to be addressed.",
    "Avoid allowing standard users to execute unapproved binaries from their `%Downloads%` folder (enforce AppLocker)."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}