Tinba

Overview

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.

What is Tinba?
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.

Infection Vectors & Threat Hunting
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 and subsequently into any running browser instances (iexplore.exe, chrome.exe, firefox.exe). It hooks network APIs (like HttpSendRequest and InternetReadFile) 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.

Forensic Analysis & Impact
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.

Known aliases

Threat reports may refer to this family under multiple names:

• zusy
• tiny_banker
• tinba.a
• win32.tinba
• bnkr
• tiny banker trojan

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to the MITRE ATT&CK framework:

Tactical Mitigations

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

• 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.

Generated Detections (Boilerplate)

These YARA and Sigma rules are auto-generated based on the family name and aliases. They must be heavily tuned before deployment in a production environment.

YARA Rule

rule MALWARE_WIN_TINBA {
    meta:
        description = "Detects Tinba (banking_trojan)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "tinba" ascii wide nocase
        $s2 = "zusy" ascii wide nocase
        $s3 = "tiny_banker" ascii wide nocase
        $s4 = "tinba.a" ascii wide nocase
        $s5 = "win32.tinba" ascii wide nocase
        $s6 = "bnkr" ascii wide nocase
        $s7 = "tiny banker trojan" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Tinba Activity
id: d63785296565855cc4d0c11588a7fc84
status: experimental
description: Detects generic indicators of the tinba malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*tinba*"
            - "*zusy*"
            - "*tiny_banker*"
            - "*tinba.a*"
            - "*win32.tinba*"
            - "*bnkr*"
            - "*tiny banker trojan*"
    condition: selection
level: medium

Containment & Response Steps

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

1. Isolate the machine from the network to prevent the exfiltration of captured login credentials and intercepted session tokens.
2. Utilize memory analysis tools (like Volatility) to identify and dump the 20KB Tinba payload injected into <code>explorer.exe</code>.
3. Enforce a mandatory password reset for all financial accounts accessed from the infected host.
4. Reimage the operating system entirely; due to its process injection, manually cleaning Tinba is highly unreliable.

What to Avoid

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

1. 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.
2. Do not allow the user to continue using the machine for 'non-financial' tasks, as the malware sniffs all web traffic indiscriminately.

References & External Analysis

• Search "tinba" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: banking_trojan)

Explore other malware families in the same category:

• Snifula
• Spyeye
• Shiz
• Carberp
• Zusy

Machine-readable

Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/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.