Multibanker
Table of Contents
Overview
Trojan:Win32/Multibanker represents a sophisticated class of financial malware designed to target multiple banking institutions simultaneously. Unlike older, single-target trojans, Multibanker utilizes dynamic configuration files pulled from a Command-and-Control (C2) server, allowing it to adapt its web injects and credential-stealing routines to intercept login attempts across dozens of different online banking portals (`T1185`).
Understanding Multibanker (Financial Fraud)
To an end-user, the infection is entirely invisible. They will navigate to their legitimate bank website, log in as usual, but the trojan silently intercepts and modifies the transaction in the background. For financial institutions, Multibanker represents a severe threat, as it frequently bypasses standard Two-Factor Authentication (2FA) by tricking the user into entering their OTP into a fake web form injected by the malware.
Execution and Web Injection Mechanics
Multibanker is typically distributed via malspam (weaponized Office documents) or exploit kits. Upon execution, it establishes persistence (often via Registry Run keys) and injects itself into browser processes (`chrome.exe`, `firefox.exe`, `iexplore.exe`) (`T1055`). It then intercepts API calls related to network traffic (like `HttpSendRequest`). When the user navigates to a targeted bank, Multibanker uses 'Web Injects' (`T1185`) to alter the HTML of the webpage in real-time, inserting extra fields asking for credit card numbers, ATM PINs, or OTPs, which are immediately exfiltrated to the attacker (`T1041`).
Indicators of Compromise & Impact
The impact is direct financial fraud and total credential compromise. Host-based IoCs include EDR alerts for process injection (specifically into browser processes), unexpected network connections from legitimate browsers to unknown IP addresses (the C2 server fetching the inject configurations), and the presence of hidden, encrypted configuration files in `%AppData%`. Network IoCs involve the browser making encrypted POST requests to the C2 server containing the stolen credentials.
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:
- 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):
| D3FEND ID | Countermeasure Name | Tactic | Countered ATT&CK | Defensive Guidance |
|---|---|---|---|---|
D3-EAF | Egress Analysis and Filtering | Isolate | T1041 | Enforce perimeter TLS inspection and alert on anomalous outbound data volume ratios transmitting over active C2 channels. |
D3-PIAD | Process Injection Analysis & Detection | Detect | T1055 | Monitor cross-process thread creation (CreateRemoteThread) and asynchronous procedure calls (QueueUserAPC). |
D3-MitBA | Man-in-the-Browser Analysis | Detect | T1185 | Deploy browser extension whitelisting and hardware-backed session binding to prevent rogue DOM and socket 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:
Tier 1 Primitive Artifact Rule (Fast Triage)
Matches raw strings and file markers. Vulnerable to binary repacking and simple obfuscation.
rule MALWARE_WIN_MULTIBANKER_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Multibanker"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "multibanker" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Tier 2 Behavioral Context Rule (Process Chains & Sigma)
Tracks parent-child process anomalies and suspicious scripting telemetry. Resilient against file renames.
title: SystemHelpDesk Detection - Multibanker (Trojan) Execution & Triage
id: 84dafa7c-afd8-57cd-802e-e340a5642f95
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Multibanker malware family. Detects suspicious execution from temporary
user directories with hidden window flags and background transfer utilities.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/multibanker
- https://malware-families-catalog.systemhelpdesk.com/defensive/downloader-dropper-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.trojan
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1185
- attack.t1041
- attack.t1055
logsource:
category: process_creation
product: windows
detection:
selection_process:
Image|endswith:
- \cmd.exe
- \powershell.exe
- \cscript.exe
- \wscript.exe
CommandLine|contains:
- AppData\Local\Temp
- -WindowStyle Hidden
- /e:jscript
- bitsadmin /transfer
condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: mediumTier 3 Attribution Fingerprint Rule (High Fidelity)
Deep signature matching distinctive operational fingerprints and payload characteristics.
rule MALWARE_WIN_MULTIBANKER_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Multibanker 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 = "multibanker" 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.
- Isolate the endpoint immediately to prevent further credential exfiltration and unauthorized transactions.
- Assume all credentials stored in or used via web browsers on the infected machine have been compromised.
- Contact financial institutions immediately to freeze accounts, report the compromise, and monitor for fraudulent transactions.
- Capture a memory dump before remediation to extract the active web inject configurations and identify the targeted banks.
What to Avoid
Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.
- Do not assume that changing the password will stop the fraud; if the malware is still active, it will simply steal the new password and any new OTPs.
- Avoid logging into any secure portals (banks, email, corporate VPN) from the infected machine until it has been completely wiped.
References & External Analysis
- Search "multibanker" on VirusTotal (External Analysis)
- Search "multibanker" on Any.Run (Sandbox Sandbox)
- Search "multibanker" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Multibanker and what threat category does it belong to?
Multibanker is classified as a Trojan. Documented across security telemetry, it is engineered to execute unauthorized operations, establish persistent footholds on target endpoints, and facilitate malicious campaigns targeting enterprise and individual environments.
How does Multibanker establish persistence and evade defensive controls?
Multibanker typically establishes persistence through registry run keys, scheduled tasks, or service installations, while evading signature-based antivirus solutions through code obfuscation, memory injection, or anti-analysis sandbox checks.
What are the essential incident response steps for mitigating a Multibanker compromise?
Security teams responding to Multibanker should immediately isolate affected endpoints from the network, perform memory triage to capture volatile forensic artifacts, audit registry and startup persistence mechanisms, revoke exposed user credentials, and restore systems from verified, clean backups.
What secondary payloads and staging behaviors are commonly associated with Multibanker?
Multibanker frequently operates as a loader or dropper designed to establish a foothold before downloading and executing secondary high-impact malware payloads. Depending on the threat actor's objectives, these dropped modules can range from ransomware and banking injects to modular infostealers and remote management backdoors.
How can security operations teams effectively detect and hunt for Multibanker across enterprise endpoints?
Defenders should hunt for Multibanker by deploying behavioral endpoint detection and response (EDR) rules that monitor suspicious process spawning (such as cmd.exe or powershell.exe spawned from office documents or temporary directories), anomalous outbound network connections from non-browser binaries, and unauthorized modifications to Windows Run keys and scheduled task registries.
How do I remove the Multibanker Trojan from Windows?
Manual removal of Multibanker is highly discouraged as it may leave persistence mechanisms intact. We recommend disconnecting the device from the internet and utilizing a professional incident response service or enterprise-grade EDR software to conduct a full forensic sweep.
Is Multibanker a virus or a Trojan?
Multibanker is classified as a Trojan. Unlike traditional viruses that infect files, modern malware like Multibanker typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Multibanker infection?
Symptoms of Multibanker can include unexpected system slowness, unauthorized outbound network traffic to unknown IP addresses, disabled security software, and suspicious background processes running from AppData or Temp directories.
Protect Your Network Against Trojans
Want to prevent Multibanker and similar threats from compromising your organization? Read our comprehensive defensive guide: Banking Trojan Protection for Businesses.
📣 Threat Intel Correction or Update?
Notice an outdated IOC, unlisted alias, or disputed attribution? Threat researchers are invited to propose an update on GitHub or contact the SystemHelpDesk research desk. All community revisions are credited in our public CHANGELOG.
Machine-readable
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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.