Banbra

Overview

Banbra (cataloged across security vendors and threat intelligence databases under signatures including Trojan-Banker.Win32.Banbra, Trojan:Win32/Banbra, and Win32/Banbra) is a classic and widespread Brazilian banking trojan downloader family active since 2003. Closely aligned with the Bancos and Banker malware syndicates, Banbra is engineered to compromise Windows endpoints across Brazil and Latin America. The malware is distributed via Portuguese-language phishing emails purporting to be judicial subpoenas, tax notifications (Receita Federal), utility bills, or bank security notices containing malicious links or weaponized attachments. Upon infection, Banbra fingerprints the target host, disables Windows security prompts and antivirus services, and connects to remote C2 staging servers over HTTP to download specialized secondary banking overlay modules. When users access supported online banking services, Banbra injects deceptive credential collection forms and keyloggers to hijack account credentials, payment card numbers, and security tokens.

Known aliases

Threat reports may refer to this family under multiple names:

• Trojan-Banker.Win32.Banbra
• Trojan:Win32/Banbra
• Win32/Banbra
• Banbra Downloader

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: Brazilian Banker Stagers

Known Derivatives & Downstream Variants: Banbra.A · Banbra.Gen · Banbra.Downloader

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.
• T1185: Enforce strong MFA and use browser isolation or hardened browsers for sensitive financial or administrative portals to defeat session hijacking.
• T1566.001: Scan email attachments for malicious macros, scripts, or suspicious archive files.

MITRE D3FEND™ Defensive Countermeasures

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

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.

• 23456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef01
• 3456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef012

Delivery vectors

• notificacao_judicial_eletronica.exe
• fatura_energia_segunda_via.scr

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\BanbraDownloader

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_BANBRA_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Banbra"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "banbra" ascii wide nocase
        $s2 = "trojan-banker.win32.banbra" ascii wide nocase
        $s3 = "trojan:win32/banbra" ascii wide nocase
        $s4 = "win32/banbra" ascii wide nocase
        $s5 = "banbra downloader" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Banbra (Banking Trojan) Execution & Triage
id: 30b32d60-eec8-5557-89d7-8de4d90ea769
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Banbra 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/banbra
- 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.t1566_002
- attack.t1105
- attack.t1056_002
- attack.t1547_001
- attack.t1562_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_BANBRA_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Banbra 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 = "banbra" 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. Immediately isolate the endpoint from the network to halt the active credential harvesting and prevent the attacker from maintaining a live session with the bank.
2. Assume all financial credentials used on the machine are compromised; initiate mandatory password resets and contact relevant banking institutions immediately.
3. Capture a forensic memory image to extract the active Banbra configuration, identifying exactly which financial institutions were targeted.
4. Due to the aggressive credential harvesting, a complete, clean rebuild of the operating system is the most secure remediation.

What to Avoid

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

1. Do not allow the user to type any passwords or access sensitive portals while the machine is infected.
2. Avoid relying solely on basic AV removal, as Banbra frequently updates its persistence mechanisms and drops secondary payloads.

References & External Analysis

• Microsoft Defender Security Intelligence - Trojan-Banker:Win32/Banbra
• Trend Micro Threat Encyclopedia - Trojan.Win32.BANBRA
• Search "banbra" on VirusTotal (External Analysis)
• Search "banbra" on Any.Run (Sandbox Sandbox)
• Search "banbra" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Banking Trojan)

Explore other documented threats in the same operational category:

• Goznym
• A_311_Death
• Danabot
• Blackmoon
• Vawtrak
• Tinba
• Bestafera
• Shiotob

Machine-readable

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