Netpass

Overview

HackTool:Win32/Netpass is a heuristic detection applied to the legitimate NirSoft utility 'Network Password Recovery' (`netpass.exe`), as well as modified variants of it. This tool is designed to recover all network passwords stored on the local system by the current logged-on user (including saved Wi-Fi keys, RDP credentials, and Outlook Exchange passwords). While it has legitimate administrative uses, threat actors and malware heavily abuse it during the post-exploitation phase to quickly harvest local credentials for lateral movement.

Understanding Netpass Abuse
To a standard user, Netpass is invisible; it is a command-line utility. For a security analyst, the execution of `netpass.exe` (or a renamed variant) by a standard user account is a massive red flag. It indicates that an attacker has gained a foothold on the endpoint and is actively dumping the Windows Credential Manager to find passwords that will allow them to pivot to other machines or servers on the domain.

Execution and Credential Harvesting Mechanics
Netpass is typically dropped onto the system by an Initial Access Broker trojan or manually copied by an attacker after establishing a reverse shell (`T1105`). The attacker executes the tool (`T1204.002`), often using command-line arguments to silently output the results to a text file (e.g., `netpass.exe /scomma %temp%\creds.csv`) (`T1059.004`). The tool queries the Windows Data Protection API (DPAPI) and the Credential Manager (`T1003`) to extract plaintext passwords that the user has opted to 'Save' or 'Remember'. The attacker then exfiltrates the resulting text file via their C2 channel.

Indicators of Compromise & Impact
The impact is the total compromise of all saved network credentials for that user profile, significantly accelerating lateral movement within the enterprise. The primary IoC is an EDR alert for the execution of a file matching the hash or metadata of the NirSoft Netpass utility, especially if executed from a temporary directory (`%Temp%` or `C:\PerfLogs`). Analysts should look for command-line arguments involving silent execution (`/scomma`, `/stext`) targeting text files.

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:

• T1003: Monitor for LSASS memory dumping or registry SAM extraction. Enable Credential Guard on Windows systems.
• T1059.004: Restrict execution of scripting languages such as PowerShell, VBScript, or Python to authorized administrators. Enforce Script Block Logging.
• T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.

MITRE D3FEND™ Defensive Countermeasures

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

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_NETPASS_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Netpass"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "netpass" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Netpass (Trojan) Execution & Triage
id: 59cbb314-2538-5291-ad7b-32aa460f5d40
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Netpass 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/netpass
- 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.t1555
- attack.t1105
- attack.t1003
- attack.t1059_004
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: medium

rule MALWARE_WIN_NETPASS_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Netpass 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 = "netpass" 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. Isolate the endpoint immediately; active credential dumping means an attacker is currently operating on the machine and attempting to move laterally.
2. Assume all passwords stored in the Windows Credential Manager (RDP, network shares, Outlook) are compromised. Enforce an immediate password reset for the affected user account.
3. Investigate EDR logs to determine *how* the Netpass utility was dropped onto the machine to identify the initial entry vector (e.g., a reverse shell or a dropper trojan).
4. Hunt across the enterprise for the specific hash of the Netpass utility to ensure the attacker hasn't copied it to other machines.

What to Avoid

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

1. Do not assume the execution was legitimate administrative activity without explicitly verifying with the IT team; attackers frequently rename these tools to blend in.
2. Avoid closing the incident simply by deleting the tool; the passwords have already been extracted and exfiltrated.

References & External Analysis

• Search "netpass" on VirusTotal (External Analysis)
• Search "netpass" on Any.Run (Sandbox Sandbox)
• Search "netpass" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Staem
• Vesenlosow
• Mudrop
• Triusor
• Sohanad
• Bitrep
• Pcmega
• Peepviewer

Machine-readable

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