Trojan:Win32/Tinba (Tiny Banker) 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 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.
Threat reports may refer to this family under multiple names:
Observed techniques used by this family, mapped to the MITRE ATT&CK framework:
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.
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
condition:
uint16(0) == 0x5a4d and any of them
}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*"
condition: selection
level: mediumOrdered checklist for responders. Adapt to your environment and engage professional support for active incidents.
Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.
Because its code is unusually small for a banking trojan.
Through web injection that captures banking login details in the browser.
Through exploit kits and phishing campaigns.
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Get this profile as JSON: https://jordanricky1604-ship-it.github.io/malware-families-catalog/api/tinba.json
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, Replit, StackBlitz, CodeSandbox, and CodePen.