Netshadow

Overview

Executive Summary

Infection Vector and Technical Capabilities

• Advanced Keylogging: NetShadow implements a sophisticated user-mode (and sometimes kernel-mode) keylogger. It hooks into the Windows API (e.g., `SetWindowsHookEx`) to intercept every keystroke before it reaches the intended application. This allows it to capture passwords entered into secure web portals, email clients, and VPN login screens.
• Screen Capture and Clipboard Monitoring: To supplement the keylogging data, the trojan periodically captures screenshots of the victim's desktop and continuously monitors the Windows clipboard, instantly stealing copied passwords or cryptocurrency wallet addresses.
• Data Exfiltration: The stolen data is aggregated into hidden, encrypted log files on the local disk. It is then periodically transmitted back to the C2 server over standard web ports (HTTPS) or via SMTP (email) to evade deep packet inspection.

Threat Assessment

Incident Response and Remediation

• Immediate Isolation: Sever the affected machine's network connection immediately to halt any active or pending data exfiltration.
• Comprehensive Credential Reset: Assume all credentials typed on the infected machine since the time of infection are fully compromised. Initiate an immediate, organization-wide password reset for the affected user, and invalidate all active session tokens.
• Forensic Analysis: Conduct a forensic review of the endpoint to determine the initial vector of compromise and to ensure NetShadow did not deploy secondary backdoors prior to detection.

Known aliases

Threat reports may refer to this family under multiple names:

• Trojan.NetShadow
• Keylogger.NetShadow
• Spyware.NetShadow

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.
• T1113: Monitor for frequent or unauthorized screen captures or clipboard reads. Restrict background applications from accessing desktop APIs.

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_NETSHADOW_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Netshadow"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "netshadow" ascii wide nocase
        $s2 = "trojan.netshadow" ascii wide nocase
        $s3 = "keylogger.netshadow" ascii wide nocase
        $s4 = "spyware.netshadow" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Netshadow (Trojan) Execution & Triage
id: 48afa99b-e83c-52fd-a815-bed8f9ee0926
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Netshadow 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/netshadow
- 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.t1056_001
- attack.t1113
- attack.t1048
- attack.t1115
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_NETSHADOW_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Netshadow 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 = "netshadow" 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. Sever network connectivity for the flagged endpoint to terminate persistent command-and-control (C2) communication channels and stop Netshadow from retrieving secondary stage payloads.
2. Capture process memory triage to detect and terminate malicious threads injected by Netshadow into legitimate system processes such as explorer.exe or svchost.exe.
3. Audit Windows Registry Run keys (HKCU\Software\Microsoft\Windows\CurrentVersion\Run) and Task Scheduler entries to locate and purge Netshadow persistence hooks.
4. Deploy updated enterprise EDR detection signatures and conduct an out-of-band endpoint scan to isolate dropped binaries and staged payloads.
5. Rotate all credentials, domain user passwords, and session cookies active on the system during the Netshadow execution timeframe.

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 incident is resolved simply because an antivirus tool removed the initial Netshadow dropper; always verify that secondary payloads and persistence hooks have been eradicated.
2. Avoid logging in with Domain Admin or privileged credentials on a machine suspected of running Netshadow until memory triage is complete.
3. Do not delay host isolation; automated lateral movement and credential dumping can occur within minutes of initial execution.

References & External Analysis

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

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Comine
• Genericrxby
• Autohk
• Ekstak
• Zebrocy
• Cryptominer
• Iezones
• Ursu

Machine-readable

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