Messengerpass
Overview
Executive Summary
MessengerPass is a classification frequently applied to a legitimate password recovery utility developed by NirSoft, designed to extract saved login credentials from various Instant Messaging (IM) clients (like MSN, Yahoo!, Google Talk, ICQ). Because it instantly retrieves passwords in clear text without requiring the user's master password, security vendors universally classify it as a "HackTool" or "Riskware." Threat actors, particularly Initial Access Brokers, heavily abuse this utility post-compromise to rapidly harvest corporate communication credentials.Infection Vector and Technical Capabilities
MessengerPass is not self-replicating malware. It is a standalone executable (`mspass.exe`) that is typically dropped onto a system by an attacker who has already gained interactive access, or it is executed silently in the background by a malicious script or a dropper Trojan. Upon execution, its capabilities are highly focused and dangerous:- Registry and File Parsing: The utility automatically scans the Windows Registry and specific application data folders (`%APPDATA%`) looking for the encrypted credential stores utilized by supported IM clients.
- Plain-Text Decryption: It leverages the Windows Data Protection API (DPAPI) or specific decryption algorithms to reverse the local encryption applied by the IM clients, instantly displaying the usernames and passwords in clear text.
- Command-Line Automation (Abuse): Attackers frequently abuse the tool's command-line interface. By executing the utility with specific flags (e.g., `/stext output.txt`), the tool runs completely silently, dumps all recovered IM passwords to a hidden text file, and exits, allowing the attacker to easily exfiltrate the file via a reverse shell.
Threat Assessment
The unauthorized execution of MessengerPass on a corporate endpoint is a critical indicator of an active credential harvesting operation. It signifies that an attacker has gained sufficient privileges to run credential-dumping tools and has successfully stolen passwords that may be reused across other corporate systems or used to impersonate employees.Incident Response and Remediation
- Contextual Investigation: Determine if the execution was authorized by IT for legitimate password recovery. If not, the endpoint must be considered actively compromised and isolated immediately.
- Trace the Execution: Utilize EDR telemetry to determine *how* the tool was executed. Identify the parent process (e.g., `cmd.exe`, `powershell.exe`, or a malicious dropper) to locate the source of the initial breach.
- Mandatory Global Credential Reset: If unauthorized execution is confirmed, all passwords stored in the user's IM clients, and any identical passwords used for Active Directory or corporate web apps, must be reset immediately.
Known aliases
Threat reports may refer to this family under multiple names:
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1555.003 T1003 T1059.003
Tactical Mitigations
Based on the techniques used by this family, consider the following defensive strategies:
- T1003: Monitor for LSASS memory dumping or registry SAM extraction. Enable Credential Guard on Windows systems.
- T1059.003: Restrict execution of Windows Command Shell (cmd.exe) and block unauthorized batch scripts.
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_MESSENGERPASS {
meta:
description = "Detects Messengerpass (trojan)"
author = "SystemHelpdesk Boilerplate Generator"
date = "2026-07-06"
strings:
$s1 = "messengerpass" ascii wide nocase
$s2 = "hacktool.mspass" ascii wide nocase
$s3 = "riskware.passwordviewer" ascii wide nocase
$s4 = "pws.nirsoft" ascii wide nocase
$s5 = "tool.messengerpass" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Sigma Rule
title: Suspicious Messengerpass Activity
id: 3fc5cdbeb2d9124a11bcc4959c7fc57d
status: experimental
description: Detects generic indicators of the messengerpass malware family.
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith:
- '\cmd.exe'
- '\powershell.exe'
CommandLine|contains:
- "*messengerpass*"
- "*hacktool.mspass*"
- "*riskware.passwordviewer*"
- "*pws.nirsoft*"
- "*tool.messengerpass*"
condition: selection
level: mediumReferences & External Analysis
- Search "messengerpass" on VirusTotal (External Analysis)
Frequently Asked Questions
How do I remove the Messengerpass Trojan from Windows?
Manual removal of Messengerpass 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 Messengerpass a virus or a Trojan?
Messengerpass is classified as a Trojan. Unlike traditional viruses that infect files, modern malware like Messengerpass typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Messengerpass infection?
Symptoms of Messengerpass 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.
Related Families (Category: trojan)
Explore other malware families in the same category:
Protect Your Network Against Trojans
Want to prevent Messengerpass and similar threats from compromising your organization? Read our comprehensive defensive guide: Banking Trojan Protection.
Machine-readable
Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/api/messengerpass.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.