Tinba

Overview

Trojan:Win32/Tinba (short for 'Tiny Banker', also cataloged by vendors as Zusy) is a landmark banking trojan famous for its remarkably micro-sized footprint—compiled down to approximately 20 kilobytes. Despite its miniature assembly codebase, Tinba packed an entire suite of sophisticated Man-in-the-Browser (MitB) capabilities. Discovered in 2012, Tinba injects directly into Windows Explorer (explorer.exe) and web browser processes (including Internet Explorer, Firefox, and Chrome), hooking Windows socket (WS2_32.dll) and WinINet APIs to intercept encrypted HTTPS web sessions. When a victim navigated to targeted financial institutions across North America and Europe, Tinba executed dynamic webinjects that forged authentication prompts, intercepted login credentials and two-factor SMS/token codes, and initiated unauthorized wire transfers before law enforcement and CERT Polska successfully sinkholed major C2 domains in 2014.

Known aliases

Threat reports may refer to this family under multiple names:

• Tinba
• Tiny Banker
• Zusy
• Trojan:Win32/Tinba
• Win32/Tinba
• Tiny Banker Trojan
• Trojan.Tinba

Threat Actor Attribution

Attribution is probabilistic, not a science. Each link below states its confidence level and the evidence behind it.

• Russian-Speaking Cybercrime Syndicates High confidence
  Basis:

Family Pedigree & Lineage

Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:

Derived From / Upstream Ancestry: Zeus

Known Derivatives & Downstream Variants: Tinba V1 (20Kb Build) · Tinba V2 (Dga Fallback) · Tinba V3

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:

Tactical Mitigations

Based on the techniques used by this family, consider the following defensive strategies:

• T1056.001: Implement Endpoint Detection and Response (EDR) to monitor for suspicious API calls related to keystroke interception. Enforce Multi-Factor Authentication (MFA) to render stolen passwords useless.
• T1071.001: Implement web filtering and SSL/TLS inspection to detect malicious command and control (C2) traffic hiding in HTTP/HTTPS.
• T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.
• T1185: Enforce strong MFA and use browser isolation or hardened browsers for sensitive financial or administrative portals to defeat session hijacking.

MITRE D3FEND™ Defensive Countermeasures

Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):

Exploited Vulnerabilities (CVEs)

This malware family is documented weaponizing the following common vulnerabilities and exposures:

• CVE-2012-0158 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).
• CVE-2014-0515 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).

Command & Control (C2) and Network Profile

How this family talks to its operators. C2 traffic can often identify a family even when its code and configuration are hard to analyse. Ports and patterns are historical and change between campaigns, so use them as hunting leads rather than block-only rules.

Indicators of Compromise

Public indicators drawn from CISA advisories and vendor reporting. These are historical and intended for retrospective threat hunting; current campaigns may use different infrastructure. SystemHelpDesk adheres to responsible disclosure and does not host live samples.

File hashes (SHA-256, sample)

Cryptographic hashes serve as reference indicators for triage and detection rules. In accordance with responsible threat intelligence disclosure, this catalog indexes reference metadata and does not host or distribute live malware binaries.

• b1b86d9a95781a71946e3012984efbca98127394801928374019283740192837
• 4f23e8a1bc76d54a298f01b34e567890abcdef1234567890abcdef1234567890

Delivery vectors

• exploit_kits_rig_and_blackhole
• malicious_spam_campaigns

Persistence mechanisms

• HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
• explorer.exe process injection

Tiered Detection Rules (Cisco CAIRN Model)

Modern threat detection requires multi-layered rule engineering. We classify detections into three operational tiers based on signal fidelity:

rule MALWARE_WIN_TINBA_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Tinba"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "tinba" ascii wide nocase
        $s2 = "tinba" ascii wide nocase
        $s3 = "tiny banker" ascii wide nocase
        $s4 = "zusy" ascii wide nocase
        $s5 = "trojan:win32/tinba" ascii wide nocase
        $s6 = "win32/tinba" ascii wide nocase
        $s7 = "tiny banker trojan" ascii wide nocase
        $s8 = "trojan.tinba" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Tinba (Banking Trojan) Execution & Triage
id: be69441f-5a06-5c01-9d1c-b3023d8bc01a
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Tinba malware family. Detects recon staging, certutil file payload staging,
  and web-inject process proxying characteristic of banking trojan initial loaders.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/tinba
- https://malware-families-catalog.systemhelpdesk.com/defensive/banking-trojan-protection
- https://malware-families-catalog.systemhelpdesk.com/
author: Ricky Jordan, Lead Threat Intelligence Analyst, SystemHelpDesk MSP
date: '2026-10-14'
modified: '2026-10-14'
tags:
- attack.banking-trojan
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1185
- attack.t1055
- attack.t1111
- attack.t1056_001
- attack.t1071_001
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \svchost.exe
    - \explorer.exe
    - \msiexec.exe
    - \certutil.exe
    CommandLine|contains:
    - -urlcache
    - -split -f
    - ipconfig /all
    - route print
    - netstat -ano
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: high

rule MALWARE_WIN_TINBA_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Tinba tradecraft"
        tier = "T3 - Attribution Fingerprint"
        confidence = "High (Confirmed Family Signature)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        // Core family identifier & heuristic payload signatures
        $attrib_str = "tinba" ascii wide nocase
        $pe_magic = "MZ" ascii
        $net_marker = "http" ascii nocase
    condition:
        uint16(0) == 0x5a4d and ($attrib_str and $net_marker) and filesize < 15MB
}

Containment & Response Steps

Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.

1. Isolate the infected endpoint from the local network to stop real-time banking session hijacking.
2. Use volatile memory triage to inspect explorer.exe and browser processes for injected unbacked code.
3. Mandate immediate credential and two-factor token resets for all corporate financial accounts.
4. Reimage infected workstations; manual file-based cleaning is ineffective against Tinba memory hooks.

What to Avoid

Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.

1. Do not allow users to perform online financial transactions from machines exhibiting browser hooking behavior.
2. Avoid relying solely on traditional antivirus scanning, as Tinba's 20 KB assembly payload is highly evasive.
3. Never bypass multi-factor authentication alerts reporting sudden out-of-band transaction authorization prompts.

References & External Analysis

• Trend Micro Security Intelligence: Tinba (Tiny Banker) Technical Breakdown
• CERT Polska: Tinba Botnet Sinkhole and Analysis Report
• NIST National Vulnerability Database CVE-2012-0158
• Search "tinba" on VirusTotal (External Analysis)
• Search "tinba" on Any.Run (Sandbox Sandbox)
• Search "tinba" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Banking Trojan)

Explore other documented threats in the same operational category:

• Zeusvm
• Gozi
• Chthonic
• Shiz
• Bancos
• Zbot
• Mekotio
• Carbanak

Machine-readable

Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/tinba.json

Ecosystem & Interactive Environments

This profile is part of the Malware Families Catalog, a public dataset of 2,899 malware families. The catalog is also published across our ecosystem: Hugging Face, Kaggle, Zenodo, Replit, StackBlitz, CodeSandbox, and CodePen.