Ribaj

Overview

Trojan:Win32/Ribaj (also cataloged in security telemetry as Trojan:MSIL/Ribaj, Win32/Ribaj, or Trojan.Ribaj) is an evasive credential-stealing trojan and backdoor designed to harvest sensitive user credentials, browser data, and authentication tokens from Windows endpoints. Distributed through malicious email attachments, cracked application archives, and secondary loader scripts, Ribaj establishes an encrypted footprint in the user profile directory (%AppData%). Upon execution, Ribaj enumerates installed web browsers (Chrome, Edge, Firefox), dumps encrypted SQLite credential databases, extracts master DPAPI keys, and harvests stored FTP and email client passwords. The trojan opens covert HTTP POST connections to remote command-and-control servers to exfiltrate harvested credential vaults and receive secondary instructions.

Known aliases

Threat reports may refer to this family under multiple names:

• Ribaj
• Trojan:Win32/Ribaj
• Trojan:MSIL/Ribaj
• Win32/Ribaj
• Trojan.Ribaj
• Ribaj Stealer

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: Win32 Password Stealer Generic Lineage

Known Derivatives & Downstream Variants: Trojan:Win32/Ribaj.A · Trojan:Msil/Ribaj.Gen · Win32/Ribaj.B

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.

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.

• a1b2c3d4e5f60718293a4b5c6d7e8f90a1b2c3d4e5f60718293a4b5c6d7e8f90
• f9e8d7c6b5a403129876543210abcdef9876543210abcdef9876543210abcdef

Delivery vectors

• Phishing emails with malicious macro attachments
• Trojanized application installers and cracks
• Secondary payload drops from exploit kits

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\RibajHost
• Scheduled Task configured to run at user authentication

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_RIBAJ_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Ribaj"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "ribaj" ascii wide nocase
        $s2 = "ribaj" ascii wide nocase
        $s3 = "trojan:win32/ribaj" ascii wide nocase
        $s4 = "trojan:msil/ribaj" ascii wide nocase
        $s5 = "win32/ribaj" ascii wide nocase
        $s6 = "trojan.ribaj" ascii wide nocase
        $s7 = "ribaj stealer" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Ribaj (Infostealer) Execution & Triage
id: 2266d221-4033-51d4-b211-fe382d923170
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Ribaj malware family. Detects browser credential database harvesting, master
  key queries, and DPAPI extraction routines typical of modern infostealers.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/ribaj
- https://malware-families-catalog.systemhelpdesk.com/defensive/infostealer-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.infostealer
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1555_003
- attack.t1539
- attack.t1056_001
- attack.t1547_001
- attack.t1071_001
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \cmd.exe
    - \powershell.exe
    - \rundll32.exe
    CommandLine|contains:
    - \Google\Chrome\User Data\Default\Login Data
    - \AppData\Roaming\Mozilla\Firefox\Profiles
    - \AppData\Local\Microsoft\Edge\User Data
    - vaultcmd.exe /list
    - dpapi
  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_RIBAJ_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Ribaj 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 = "ribaj" 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. Instantly isolate the endpoint from the network to halt the active exfiltration of stolen credentials and sensitive files.
2. Force a global password reset for all user accounts, prioritizing corporate VPN access, email, and financial portals.
3. Utilize EDR or memory forensics to identify and terminate the legitimate processes (like <code>explorer.exe</code>) that have been injected with the Ribaj payload.
4. Rebuild the operating system from a known-clean image to ensure complete eradication of the backdoor.

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 continue working on the infected machine, as the active keylogger will capture any new credentials entered.
2. Avoid relying solely on network blocks, as Ribaj frequently utilizes Domain Generation Algorithms (DGAs) or dynamic DNS to shift its C2 infrastructure.

References & External Analysis

• Microsoft Defender Threat Encyclopedia - Trojan:Win32/Ribaj
• Trend Micro Threat Encyclopedia - Trojan.Win32.Ribaj
• Kaspersky Threat Intelligence - Trojan-PSW.Win32.Ribaj
• Search "ribaj" on VirusTotal (External Analysis)
• Search "ribaj" on Any.Run (Sandbox Sandbox)
• Search "ribaj" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Infostealer)

Explore other documented threats in the same operational category:

• Redline
• Hploki
• Berbew
• Papras
• Pirminay
• Wsgame
• Chisburg
• Mintluks

Machine-readable

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