{
  "family": "oficla",
  "sample_count": 2,
  "category": "trojan",
  "description": "Trojan:Win32/Oficla (also widely known as Sasfis) is a historically massive botnet and trojan downloader that peaked in activity between 2010 and 2012. Its primary function was to compromise endpoints and turn them into 'zombies' within the Oficla botnet. These zombies were then rented out to other cybercriminals to silently download and execute secondary payloads (`T1105`), most notoriously Fake Antivirus (Rogue software), spam bots (like Rustock), and banking trojans (like Zeus).<br><br><b>Understanding Oficla (Sasfis Botnet Operations)</b><br>To an end-user, an Oficla infection was usually silent, noticeable only when the secondary payload (like a screaming Fake AV pop-up) executed. For a security operations center (SOC), Oficla represents a critical breach. If Oficla is detected, the system must be considered fully compromised by multiple, unknown threat actors, as the botnet operators frequently sold access to the same machine to multiple buyers.<br><br><b>Execution and C2 Mechanics</b><br>Oficla was primarily distributed via massive spam campaigns (`T1566.001`), often disguised as fake delivery invoices (FedEx, UPS) containing malicious executables inside ZIP files, or via exploit kits on compromised websites. Upon execution, it injects its code into `explorer.exe` or `svchost.exe` (`T1055`) to hide its activity and establishes persistence via the Registry Run keys. It communicates with its C2 servers using HTTP POST requests, often employing a fast-flux DNS network to hide the true location of the servers. The C2 server responds with encrypted URLs pointing to the secondary payloads the bot must download and execute.<br><br><b>Indicators of Compromise & Impact</b><br>The primary impact is the deployment of severe secondary malware and incorporation into a criminal botnet. Host-based IoCs include EDR alerts for process injection (particularly into `explorer.exe`) and the rapid, silent downloading and execution of unknown binaries into the `%Temp%` directory. Network IoCs include a distinctive 'beaconing' pattern of HTTP POST requests containing encrypted system profiling data sent to rapidly changing, algorithmically generated domains (DGAs).",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1547.001",
    "T1105",
    "T1566.001",
    "T1055"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1105",
      "name": "Ingress Tool Transfer (The primary function: downloading other malware)",
      "tactic": "Command and Control"
    },
    {
      "id": "T1055",
      "name": "Process Injection (Hiding within explorer.exe or svchost.exe)",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1566.001",
      "name": "Phishing: Spearphishing Attachment (Primary distribution method)",
      "tactic": "Initial Access"
    },
    {
      "id": "T1547.001",
      "name": "Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder",
      "tactic": "Persistence"
    }
  ],
  "containment_steps": [
    "Immediately isolate the compromised endpoint from the network to sever its connection to the Oficla C2 infrastructure.",
    "Assume the system is heavily compromised by multiple malware families; initiate a full reimaging of the machine rather than attempting cleanup.",
    "Analyze DNS and proxy logs to identify the C2 domains Oficla contacted and block them enterprise-wide to prevent further botnet registration.",
    "Implement email filtering rules to block executable attachments (e.g., `.exe`, `.scr` inside `.zip` files) commonly used to distribute the malware."
  ],
  "what_to_avoid": [
    "Do not assume the incident is resolved by merely deleting the initial Oficla executable; it is guaranteed that secondary payloads were downloaded.",
    "Avoid trusting the integrity of the operating system after an Oficla infection; full wipe and reinstall is the only safe remediation."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}