Removal instructions for malicious programs from the Duke malware family

What kind of malware is Duke?

Duke is the general name for malware toolsets used by the APT29 APT (Advanced Persistent Threat) actor, also known as The Dukes, Cloaked Ursa, CozyBear, Nobelium, and UNC2452. APT29 is a Russian state-sponsored group associated with the Foreign Intelligence Service of the Russian Federation (SVR RF). The group is politically and geopolitically motivated; it deals with intelligence gathering and cyber-espionage.

The Duke malware family encompasses a broad range of malicious programs, including system backdoors, loaders, data stealers, process disruptors, and others.

The latest spam campaign linked to The Dukes group occurred in 2023 and implemented malicious PDF documents disguised as diplomatic invitations from the German embassy. This email campaign targeted Foreign Affairs ministries of countries aligned with NATO.

Duke malware toolset overview

The Dukes APT actor has been in operation since at least 2008, and throughout the years, the group has implemented a wide variety of tools. The following is a chronological listing of some of the better-known toolsets utilized by this threat actor.

PinchDuke – consists of several loaders intended to infiltrate additional malicious components or programs into compromised systems.

It also encompasses a grabber for file exfiltration and a credential stealer. The latter targets data associated with the Microsoft Authenticator (passport.net), email clients (Mail.ru, Mozilla Thunderbird, Outlook, The Bat!, Yahoo Mail), browsers (Internet Explorer, Mozilla Firefox, Netscape Navigator), messaging services (Google Talk), etc.

GeminiDuke – includes loader capabilities and multiple persistence-ensuring mechanisms. It likewise boasts stealer functionalities predominantly used for device configuration data collection.

Information of interest includes: user accounts, installed drivers and software, running processes, programs/services launched at startup, network settings, folders/files present in specific locations, recently executed programs and opened folders/files, etc.

CosmicDuke (aka BotgenStudios, NemesisGemina, Tinybaron) – comprises several loaders, multiple persistence-ensuring components, and a module for privilege escalation.

The largest part of this malware is an information-stealer with abilities to: exfiltrate files with specific extensions, export cryptographic certificates (including private keys), take screenshots, record keystrokes (keylogging), extract log-in credentials (browsers, email clients, messengers), and acquire clipboard (copy-paste buffer) contents.

MiniDuke – is a malware with several variants, including a loader, downloader, and backdoor. Chiefly, MiniDuke is used to prepare a system for further infection and/or facilitate it.

CozyDuke (aka Cozer, CozyBear, CozyCar, EuroAPT) – is primarily a backdoor that opens a "backdoor" for further infections, particularly its own modules. To this effect, it employs a dropper and multiple modules for persistence.

Other components include ones for extracting system data, executing basic Cmd.exe commands, taking screenshots, and stealing log-in credentials. However, CozyDuke can also infiltrate/execute other files – hence, it could be used to (theoretically) cause just about any type of malware infection.

OnionDuke – is a modular malware with a variety of potential configurations. It has loader and dropper capabilities. The program implements several different information-stealing modules, e.g., for passwords and other data.

It also has a component for launching DDoS (Distributed Denial-of-Service) attacks. Another module is designed to use hijacked social networking accounts for launching spam campaigns (potentially to spread the infection further).

SeaDuke (aka SeaDaddy, SeaDask) – is a cross-platform (Windows and Linux) backdoor. It is a relatively basic toolset with the main objective of executing infiltrated files, thus furthering the infection.

HammerDuke (aka HAMMERTOSS, Netduke) – is a simple backdoor. Its known use has been exclusively as a secondary backdoor that follows a CozyDuke infection.

CloudDuke (aka CloudLook, MiniDionis) – has two backdoor versions. This malware also includes downloader and loader capabilities. Typically, it downloads/installs payloads from predetermined locations, either from the Web or a Microsoft OneDrive account.

It is pertinent to mention that unless The Dukes APT actor ceases operations, the likelihood of new malware toolset implementation is high.

Generally, sophisticated malware can cause multiple system infections, decreased system performance or failure, data loss, severe privacy issues, financial losses, and identity theft. However, malicious software leveraged against highly sensitive targets can pose threats of even greater significance.

Malware in general

Malware can be narrowly tailored for a specific purpose or be incredibly versatile. While malicious software is most commonly used to generate revenue, its application can vary. Attacks can be motivated by attackers' personal relationships and grudges or political/geopolitical reasons and circumstances.

However, regardless of how malware operates – its presence on a system endangers device integrity and user safety. Therefore, all threats must be eliminated immediately upon detection.

We have analyzed thousands of malware samples; JanelaRAT, Agniane stealer, NightClub, Jorik, XWorm RAT, and WikiLoader are just a few of our newest articles on malicious programs.

How did Duke infiltrate my computer?

The latest 2023 campaign undertaken by APT29 (The Dukes) utilized spam emails in targeted attacks. The spam was sent to Foreign Affairs ministries of interest to the Russian Federation (i.e., NATO-aligned bodies). The emails contained malicious PDF attachments masquerading as diplomatic invites from a German embassy.

One of the spam operations did not include a payload; the document titled "Day of German Unity" sent a notification to the attackers once the email attachment was opened. This suggests that it could have been an operation for reconnaissance or a test to survey the lure's success rates.

The other campaign distributed a PDF with the "Farewell to Ambassador of Germany" filename containing a Duke malware variant. This document had JavaScript code embedded into it, which was implemented to deliver a multi-staged payload in an HTML format.

If the PDF was opened in Adobe Acrobat (or a similar reader), the user gets queried about the embedded code and its execution. If the victim permitted it, a malicious HTML document titled "Invitation_Farewell_DE_EMB" was launched.

The chain then progressed to the retrieval of a ZIP archive containing a virulent HTA (HTML Application). The chain moved through several more stages until Duke malware was successfully infiltrated.

The Dukes group has been around for well over a decade and has used a variety of techniques to proliferate their malicious programs. Therefore, the malware toolsets described in this article can arrive in different infection chains, as well as in various files and lures.

This APT actor has been linked to a similar spam campaign, wherein the bait was disguised as diplomatic invitations from a Norwegian embassy, and this operation likewise targeted entities associated with Foreign Affairs. An entirely different campaign connected to APT29 used Torrent files to spread OnionDuke back in 2013-2015.

To expand upon the most widely used malware distribution techniques in general: malicious software is primarily proliferated via malicious attachments/links in spam mail (e.g., emails, DMs/PMs, SMSes, etc.), drive-by (stealthy/deceptive) downloads, untrustworthy download channels (e.g., freeware and third-party sites, P2P sharing networks, etc.), online scams, malvertising, illegal software activation tools ("cracks"), and fake updates.

Some malicious programs can even self-spread through local networks and removable storage devices (e.g., external hard drives, USB flash drives, etc.).

How to avoid installation of malware?

We highly recommend treating incoming emails and other messages with caution. Attachments or links found in suspect/irrelevant mail must not be opened, as they can be infectious. We advise using post-2010 Microsoft Office versions since they have the "Protected View" mode that prevents automatic macro command execution.

Another recommendation is to be careful while browsing since fake and malicious online content usually appears genuine and harmless.

Additionally, all downloads must be performed from official and verified channels. It is just as important to activate and update programs by using functions/tools provided by legitimate developers, as those acquired from third-parties may contain malware.

We must emphasize that having a reputable anti-virus installed and kept up-to-date is essential to device and user safety. This software must be used to run regular system scans and to remove threats and issues. If you believe that your computer is already infected, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate infiltrated malware.

Known toolset components and modules:

PinchDuke toolset:

• Data stealer
• Loader (multiple)

GeminiDuke toolset:

• Data stealer
• Loader
• Persistence-ensuring component (multiple)

CosmicDuke toolset:

• Data stealer
• Loader (multiple)
• Persistence-ensuring component (multiple)
• Privilege escalation component

MiniDuke toolset:

• Backdoor
• Downloader
• Loader

CozyDuke toolset:

• Backdoor
• Data stealers (screenshots, passwords, password hashes)
• Dropper
• Persistence-ensuring component (multiple)

OnionDuke toolset:

• Data stealers (passwords, etc.)
• DDoS
• Dropper
• Loader
• Social networking spam

SeaDuke toolset:

• Backdoor

HammerDuke toolset:

• Backdoor

CloudDuke toolset:

• Backdoor (two variants)
• Downloader
• Loader

Malicious PDF attachment distributing Duke malware variant:

How to remove malware manually?

Most trojan infections can be removed by running a full system scan with Combo Cleaner. The full manual procedure below is for cases where automatic removal failed, where you want to verify a scan caught everything, or where the threat has multiple persistence points.

Tools you'll need

Combo Cleaner Antivirus 7-days free trial

Recommended primary scanner. VB100 certified. The 7-day free trial is available.

Microsoft Defender Offline Free · built-in

Built into Windows. Boots to a clean environment to catch rootkits.

Process Explorer Free

From Microsoft Sysinternals. Better than Task Manager - shows full paths and signatures.

Autoruns Free

From Microsoft Sysinternals. Lists every place malware can persist on your system.

Microsoft Safety Scanner (MSERT) Free

Official Microsoft on-demand scanner. Always-current signatures - expires every 10 days.

Phase 1~ 5 min

Contain - limit the damage

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1

Disconnect from the network

30 secNo tool needed

Unplug your Ethernet cable and turn off Wi-Fi. If you're on a laptop, the airplane-mode key works fastest.

Why this matters

Many trojans exfiltrate data - saved browser passwords, banking sessions, screenshots - and accept remote commands. Cutting the network stops both immediately. Keep it disconnected until Phase 4.

2

Boot into Safe Mode with Networking

3 min

Safe Mode loads a minimal set of drivers and stops most malware from auto-running. "With Networking" lets you download tools - re-enable Wi-Fi only after you've booted in.

Windows 11

Open Settings → System → Recovery. Click Restart now next to Advanced startup.

Your computer will restart into the "Choose an option" menu. Click Troubleshoot → Advanced options → Startup Settings → Restart. After the second reboot, press 5 or F5.

Windows 10

Click the Windows logo, hold Shift, click the Power icon and choose Restart. In the Choose an option screen, click Troubleshoot → Advanced options → Startup Settings → Restart. Press F5.

Windows 8

Go to the Start Screen, type Advanced, select Settings → Advanced startup options → Restart now → Troubleshoot → Advanced options → Startup settings → Restart → F5.

Note: Windows 8 reached end-of-life in January 2023 - running on it puts you at much higher risk of reinfection.

Windows 7

Click Start → Shut Down → Restart → OK. As the system boots, press F8 repeatedly until the Windows Advanced Options menu appears, then choose Safe Mode with Networking.

Note: Windows 7 reached end-of-life in January 2020 - running on it puts you at much higher risk of reinfection.

Phase 2~ 15 min

Identify - find what's hiding

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3

Inspect running processes with Process Explorer

Tool: Process Explorer5 min

Download Process Explorer from Microsoft Sysinternals. Run it as Administrator. Click Options → Verify Image Signatures and View → Lower Pane View → DLLs.

Sort by "Verified Signer." Anything unsigned running from %AppData%, %LocalAppData%, %Temp%, or %ProgramData% is suspicious. Right-click → Properties to see the full image path. Right-click → "Search Online" to look up unfamiliar process names.

Why not just Task Manager

Task Manager hides full file paths, doesn't show digital signatures, and groups processes in ways that make malware easy to miss. Process Explorer is the same tool Microsoft engineers use.

4

Map every persistence point with Autoruns

Tool: Autoruns 14.x10 min

Download Autoruns. Right-click Autoruns.exe and choose Run as administrator - without elevation, Autoruns can't inspect protected registry hives.

In the menu, open Options → Hide Microsoft Entries and Options → Hide Empty Locations, then click Refresh.

Modern trojans don't just live in startup. Walk through these tabs and look for unsigned or unfamiliar entries:

• Logon - classic Run/RunOnce keys
• Scheduled Tasks - frequent hiding spot, especially tasks with PowerShell, MSHTA, or rundll32 actions
• Services - unsigned services in non-Microsoft folders
• WMI - Event Subscriptions are a stealthy persistence mechanism (MITRE T1546.003)
• Image Hijacks - Image File Execution Options "Debugger" abuse
• AppInit - DLLs loaded into every GUI process
• Browser plug-ins - unsigned add-ons across all installed browsers

Pro tip

Right-click any suspicious entry → "Jump to Image" to see the actual file. Right-click → "Search Online" opens VirusTotal for the file hash. Don't delete yet - just write down the file paths and entry names. We'll remove them after the scans.

5

Check the hosts file and DNS settings

3 minBuilt into Windows

Trojans often redirect bank, antivirus, and update domains to attacker-controlled servers by editing the hosts file or DNS settings.

Hosts file: Open Notepad as Administrator and open C:\Windows\System32\drivers\etc\hosts. Legitimate entries are commented with #. Any uncommented IP-to-domain mapping is suspicious - especially redirects for microsoft.com, windowsupdate, or your bank.

DNS settings: Open Command Prompt as Administrator and run ipconfig /all. Confirm your DNS servers point to your ISP, your router, or a known public resolver (Cloudflare 1.1.1.1, Google 8.8.8.8). Then open Settings → Network & internet → [your adapter] → DNS server assignment and verify both DNS and DNS over HTTPS (DoH) settings haven't been hijacked.

Why this matters

A clean PC with hijacked DNS is still a compromised PC. You'll think you're at chase.com and you'll be at the attacker's clone.

Phase 3~ 60-90 min

Remove - three scans, one cleanup

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No single antivirus catches everything. The order below is intentional: offline scan first (catches rootkits before Windows fully loads), then on-demand scanners on the running system, then manual cleanup of anything they missed.

6

Run Microsoft Defender Offline

Tool: Built into Windows15 min

Reboot to normal Windows. Open Windows Security → Virus & threat protection → Scan options. Select Microsoft Defender Antivirus (offline scan) and click Scan now. Your computer will restart into a stripped-down environment and scan before the full operating system loads.

Why this comes first

Rootkits and bootkits hide from any scanner running on the same Windows session that's already infected. A pre-boot offline scan sees the disk before the malware can hide itself.

Recommended antivirus

Combo Cleaner

VB100 certified. Includes anti-trojan, registry/persistence scanning, anti-spyware in one pass. The 7-day free trial is available.

Download Combo Cleaner

7

Run Combo Cleaner full system scan

Tool: Combo Cleaner20-40 min

Install Combo Cleaner and run a full system scan (not the quick scan). Let it complete fully, review the detected threats, and apply the recommended actions. Combo Cleaner will quarantine known trojans and registry persistence.

8

Run Microsoft Safety Scanner as a second-opinion scan

Tool: Microsoft Safety Scanner15 min

Download Microsoft Safety Scanner (MSERT.exe), Microsoft's free on-demand tool. The binary expires every 10 days, which means every download has the latest signatures. Run a full scan after Combo Cleaner to catch anything one engine alone might miss.

Why a second scan

Different scanning engines catch different threats. Running an additional Microsoft scan after Combo Cleaner is the single most underused verification step in malware removal.

9

Manually remove anything still listed in Autoruns

Tool: Autoruns10 min

Reopen Autoruns. Anything you flagged in Step 4 that's still present hasn't been caught by the automated scans. For each remaining suspicious entry: right-click → Delete in Autoruns (this removes the persistence registration), then navigate to the file path and delete the actual file. Empty the Recycle Bin.

Important

Some malware files reappear after deletion because something else on the system recreates them. If you delete a file and it returns within minutes, you have a remaining persistence point that Autoruns didn't show - usually a service or scheduled task running under SYSTEM. Re-run the scans from Steps 6-8 or proceed to a clean install (see end of guide).

Phase 4~ 15 min

Recover - restore browsers and security

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10

Reset browsers and clear notification permissions

5 min

Trojans and adware frequently hijack browsers - change the default search engine, install rogue extensions, or grant themselves notification permissions to keep displaying scam pop-ups even after the malware is gone.

• Chrome: visit chrome://settings/reset and click "Restore settings to their original defaults." Then visit chrome://settings/content/notifications and remove any unfamiliar sites.
• Edge: visit edge://settings/reset. Then check edge://settings/content/notifications.
• Firefox: open about:support and click Refresh Firefox (Firefox uses "Refresh," not "Reset"). Then check Settings → Privacy & Security → Permissions → Notifications.

Review installed extensions in each browser and remove anything you don't recognize, especially extensions you didn't install yourself.

11

Re-enable Defender, Tamper Protection, and update everything

10 min

Many trojans disable security software. Open Windows Security → Virus & threat protection → Manage settings and confirm Real-time protection, Cloud-delivered protection, and Tamper Protection are all turned on. Tamper Protection prevents malware from disabling Defender silently.

Then run Windows Update (Settings → Windows Update → Check for updates) and update your browsers and applications. The infection vector that let the trojan in originally usually involves outdated software.

Phase 5~ 15 min + 7 days

Verify & secure

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12

Change passwords from a clean device

20 min⚠ Critical

If the trojan was an info-stealer (Lumma, RedLine, Vidar, and similar are extremely common), assume every password saved in your browser is compromised. Change them from a different, known-clean device - your phone is fine if it's not infected.

Recommended order:

1. Primary email first - it's the recovery hub for everything else
2. Banking and financial accounts
3. Password manager master password (if you use one)
4. Social media, shopping, and remaining accounts

Where available, enable phishing-resistant multi-factor authentication (passkeys / FIDO2 hardware keys / authenticator apps) - SMS-based MFA is bypassable by sophisticated attackers.

13

Verify the clean and monitor for 7 days

5 min + 1 week monitoring

Reconnect to the network and run one final full scan with Combo Cleaner. Open Task Manager (Ctrl + Shift + Esc) and switch to the Startup apps tab - confirm nothing suspicious has reappeared.

Over the next 7 days, watch for symptom recurrence: unexpected high CPU usage, unknown processes returning, browser redirects, or pop-ups. If anything returns, you missed a persistence point and the procedure needs to be repeated - or you may have a deeper compromise that requires a clean install.

When to clean install Windows instead

Manual removal isn't always the right answer. Reinstalling Windows from scratch is the only way to be 100% certain when:

• The malware reappears after every removal attempt
• A bootkit or UEFI rootkit was detected (this class of threat sits below the operating system and survives a normal Windows reinstall)
• A confirmed credential-theft trojan ran with administrator privileges (Lumma, RedLine, Vidar) - the system likely has multiple unknown payloads
• The PC is used for online banking, business email, or anything where partial doubt isn't acceptable

A clean install is a 30-60 minute process: Windows 11 reinstall via Settings → System → Recovery → Reset this PC → Remove everything → Cloud download. Back up documents to external storage first, scan the backup with Combo Cleaner before restoring it, and reinstall applications fresh - never restore them from a backup of the infected system.

Important: Manual removal requires advanced computer skills. If you're not confident identifying system files from malicious files, run an automated scan with Combo Cleaner and Windows Defender and stop there - that path catches the vast majority of consumer trojans without the risk of breaking Windows by deleting the wrong file.

Frequently Asked Questions (FAQ)

My computer is infected with Duke malware, should I format my storage device to get rid of it?

Generally, malware removal does not necessitate formatting.

What are the biggest issues that Duke malware can cause?

The threats posed by an infection depend on the malware's capabilities and the cyber criminals' modus operandi. Duke malware family consists of toolsets that are designed for varied purposes, ranging from additional malicious content download/installation to data extraction.

Typically, high-risk infections carry the following threats: multiple system infections, decreased system performance or failure, data loss, serious privacy issues, significant financial losses, and identity theft. Duke toolsets are used by the APT29 group, which is backed by the Russian state. Attacks motivated by political/geopolitical reasons may pose even greater threats.

What is the purpose of Duke malware?

As mentioned in the previous answer, Duke malicious programs are used by a Russian state-sponsored group that has connections to the Foreign Intelligence Service of the Russian Federation (SVR RF). Hence, these malware toolsets are used in attacks centered on intelligence gathering and cyber-espionage with a significant political/geopolitical element to them.

In general, malware is primarily used for profit; other reasons include the cyber criminals' amusement, personal vendettas, process disruption (e.g., websites, services, companies, etc.), and hacktivism.

How did Duke malware infiltrate my computer?

Duke malware toolsets have been proliferated using various techniques. The latest 2023 campaign entailed spam emails carrying malicious PDFs disguised as diplomatic invites from a German embassy. This campaign targeted Foreign Affairs ministries aligned with NATO.

However, other lures and distribution methods are likely. The most commonly used techniques include: spam mail, online scams, malvertising, dubious download channels (e.g., freeware and free file-hosting sites, P2P sharing networks, etc.), illegal software activation tools ("cracks"), and fake updates. Furthermore, some malicious programs can self-proliferate via local networks and removable storage devices.

Will Combo Cleaner protect me from malware?

Yes, Combo Cleaner is capable of detecting and eliminating most of the known malware infections. Note that since high-end malicious programs tend to hide deep within systems – running a full system scan is paramount.