{
  "family": "tinba",
  "sample_count": 1531,
  "category": "banking_trojan",
  "description": "Trojan:Win32/Tinba (also known as the **Tiny Banker Trojan**) is renowned in the cybersecurity community as one of the smallest, yet most effective, banking trojans ever created, with its core executable often weighing in at around 20 kilobytes.<br><br><b>What is Tinba?</b><br>For end-users, Tinba is an invisible financial parasite. For malware analysts, it is a marvel of assembly language optimization. Despite its tiny file size, Tinba packs a full suite of banking trojan capabilities, including web injects, Man-in-the-Browser (MitB) interception, network sniffing, and encrypted C2 communications. Its small footprint allows it to evade many heuristic scanners and execute incredibly fast.<br><br><b>Infection Vectors & Threat Hunting</b><br>Tinba is typically delivered via exploit kits (such as Blackhole or RIG) targeting outdated browser plugins, or dropped by secondary malware downloaders. Once executed, it immediately injects itself into <code>explorer.exe</code> and subsequently into any running browser instances (<code>iexplore.exe</code>, <code>chrome.exe</code>, <code>firefox.exe</code>). It hooks network APIs (like <code>HttpSendRequest</code> and <code>InternetReadFile</code>) to monitor all outbound web traffic. Threat hunters will struggle to find a large binary on disk; instead, they must look for anomalous code blocks injected into the memory space of legitimate Windows processes.<br><br><b>Forensic Analysis & Impact</b><br>The primary impact is the theft of financial credentials and the interception of sensitive data. Tinba's web injects are highly customizable; when a victim visits a targeted bank, the malware alters the HTML to ask for additional information (like social security numbers or credit card pins). Incident responders should utilize memory forensics to extract the injected Tinba payload and its RC4-encrypted configuration file, which contains the list of targeted banking URLs.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "zusy",
    "tiny_banker",
    "tinba.a",
    "win32.tinba",
    "bnkr",
    "tiny banker trojan"
  ],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "Why is Tinba called 'Tiny Banker'?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Because its code is unusually small for a banking trojan."
      }
    },
    {
      "@type": "Question",
      "name": "How does Tinba steal credentials?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Through web injection that captures banking login details in the browser."
      }
    },
    {
      "@type": "Question",
      "name": "How is Tinba distributed?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Through exploit kits and phishing campaigns."
      }
    }
  ],
  "faq_count": 3,
  "mitre_attack": [
    "T1105",
    "T1111",
    "T1027",
    "T1055",
    "T1185"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1055",
      "name": "Process Injection",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1185",
      "name": "Browser Session Hijacking",
      "tactic": "Collection"
    },
    {
      "id": "T1111",
      "name": "Two-Factor Authentication Interception",
      "tactic": "Credential Access"
    },
    {
      "id": "T1027",
      "name": "Obfuscated Files or Information",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1105",
      "name": "Ingress Tool Transfer",
      "tactic": "Command and Control"
    }
  ],
  "containment_steps": [
    "Isolate the machine from the network to prevent the exfiltration of captured login credentials and intercepted session tokens.",
    "Utilize memory analysis tools (like Volatility) to identify and dump the 20KB Tinba payload injected into <code>explorer.exe</code>.",
    "Enforce a mandatory password reset for all financial accounts accessed from the infected host.",
    "Reimage the operating system entirely; due to its process injection, manually cleaning Tinba is highly unreliable."
  ],
  "what_to_avoid": [
    "Avoid running standard file-based AV scans to prove the machine is clean; Tinba's small footprint and memory-resident nature often bypass these scans.",
    "Do not allow the user to continue using the machine for 'non-financial' tasks, as the malware sniffs all web traffic indiscriminately."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}