Dothetuk
Table of Contents
Overview
Dothetuk (cataloged across security vendors and threat intelligence databases under signatures including Trojan:MSIL/Dothetuk.A, Adware:Win32/Dothetuk, and Spyware.Dothetuk) is a hybrid .NET MSIL infostealer, spyware, and adware framework active since 2017. Disseminated primarily through deceptive software bundlers, cracked applications, and weaponized email attachments, Dothetuk executes dual-purpose malicious routines. On infected systems, the malware establishes persistence through registry run entries, captures desktop screenshots, logs keystrokes, and extracts cached credentials from web browsers. Concurrently, Dothetuk modifies web browser shortcuts and injects intrusive affiliate advertisements to monetize traffic while exfiltrating harvested user credentials to remote attacker-controlled servers.
Known aliases
Threat reports may refer to this family under multiple names:
Family Pedigree & Lineage
Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:
Known Derivatives & Downstream Variants: Trojan:Msil/Dothetuk.A · Adware:Win32/Dothetuk
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1555.003 · T1056.001 · T1113 · T1185 · T1547.001 · T1071.001 · T1082
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.
- T1071.001: Implement web filtering and SSL/TLS inspection to detect malicious command and control (C2) traffic hiding in HTTP/HTTPS.
- T1113: Monitor for frequent or unauthorized screen captures or clipboard reads. Restrict background applications from accessing desktop APIs.
- T1185: Enforce strong MFA and use browser isolation or hardened browsers for sensitive financial or administrative portals to defeat session hijacking.
MITRE D3FEND™ Defensive Countermeasures
Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):
| D3FEND ID | Countermeasure Name | Tactic | Countered ATT&CK | Defensive Guidance |
|---|---|---|---|---|
D3-MFA | Multi-factor Authentication | Harden | T1056.001 | Enforce FIDO2 / WebAuthn physical tokens to render keystroke-intercepted passwords useless. |
D3-WAF | Web Content Filtering & Inspection | Filter | T1071.001 | Block newly registered domains (NRDs) and inspect HTTP Host and URI headers for known C2 profiles. |
D3-SDA | System Discovery Analysis | Detect | T1082 | Alert on rapid enumerations of systeminfo, hostname, and registry hardware trees in short intervals. |
D3-SD | Screen Capture Detection | Detect | T1113 | Monitor desktop graphics API calls (BitBlt, GetDC) triggered by non-standard background threads. |
D3-MitBA | Man-in-the-Browser Analysis | Detect | T1185 | Deploy browser extension whitelisting and hardware-backed session binding to prevent rogue DOM and socket injection. |
D3-RPM | Registry Persistence Monitoring | Detect | T1547.001 | Audit and restrict write privileges to user and machine-level Registry Run/RunOnce keys using Endpoint Privilege Management. |
D3-CVH | Credential Vault Hardening | Harden | T1555.003 | Enable DPAPI master key audit logging and isolate browser SQLite database files within virtualization-based security containers. |
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:
Tier 1 Primitive Artifact Rule (Fast Triage)
Matches raw strings and file markers. Vulnerable to binary repacking and simple obfuscation.
rule MALWARE_WIN_DOTHETUK_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Dothetuk"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "dothetuk" ascii wide nocase
$s2 = "trojan:msil/dothetuk.a" ascii wide nocase
$s3 = "adware:win32/dothetuk" ascii wide nocase
$s4 = "spyware.dothetuk" ascii wide nocase
$s5 = "win32/dothetuk" ascii wide nocase
$s6 = "msil.dothetuk" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Tier 2 Behavioral Context Rule (Process Chains & Sigma)
Tracks parent-child process anomalies and suspicious scripting telemetry. Resilient against file renames.
title: SystemHelpDesk Detection - Dothetuk (Infostealer) Execution & Triage
id: 600ae68c-75ea-54e3-867a-2ff1e896dedc
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Dothetuk 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/dothetuk
- 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.t1056_001
- attack.t1113
- attack.t1185
- attack.t1547_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: highTier 3 Attribution Fingerprint Rule (High Fidelity)
Deep signature matching distinctive operational fingerprints and payload characteristics.
rule MALWARE_WIN_DOTHETUK_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Dothetuk 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 = "dothetuk" 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
}References & External Analysis
- Microsoft Defender Threat Encyclopedia - Trojan:MSIL/Dothetuk.A
- Search "dothetuk" on VirusTotal (External Analysis)
- Search "dothetuk" on Any.Run (Sandbox Sandbox)
- Search "dothetuk" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Trojan:MSIL/Dothetuk.A?
Dothetuk is a .NET-based information stealer and adware trojan that steals credentials, captures keystrokes, and injects ads.
What sensitive information does Dothetuk harvest from victims?
It harvests browser passwords, typed keystrokes, desktop screenshots, and system configuration data.
How is Dothetuk distributed to endpoints?
Through bundled third-party freeware installers, deceptive software cracks, and malicious email links.
Does Dothetuk modify web browser settings?
Yes, it modifies browser shortcut arguments and defaults to redirect traffic through affiliate ad networks.
How can victims eliminate Dothetuk from an infected system?
Run an offline scan with Microsoft Defender, reset web browser shortcuts, and change critical account passwords.
How do I remove Dothetuk from Windows?
Manual removal of Dothetuk 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.
What are the main symptoms of a Dothetuk infection?
Symptoms of Dothetuk 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.
Protect Your Network Against Infostealers
Want to prevent Dothetuk and similar threats from compromising your organization? Read our comprehensive defensive guide: InfoStealer Protection & Remediation.
📣 Threat Intel Correction or Update?
Notice an outdated IOC, unlisted alias, or disputed attribution? Threat researchers are invited to propose an update on GitHub or contact the SystemHelpDesk research desk. All community revisions are credited in our public CHANGELOG.
Machine-readable
Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/dothetuk.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.