How to remove MassLogger malware from operating systems

What is MassLogger?

MassLogger (also known as Mass Logger) is a malicious program classified as a keylogger and 'stealer malware'. The primary purpose of MassLogger is data extraction (i.e., it steals information). The data targeted by this malware depends on the cyber criminals using it.

Since this keylogger/stealer is available for purchase, the threat actors operating it can be varied, unconnected to one another, and have different goals. This program is highly dangerous software, and therefore is it crucial to remove MassLogger infections immediately.

MassLogger malware overview

Operating as a keylogger, MassLogger can record key strokes. This puts the privacy and security of any typed information at risk. Keylogging functionalities are typically used to steal log-in credentials (i.e., usernames and passwords) of various accounts in order to hijack them.

Financial information, such as banking account and/or credit card details are of interest as well. In its capacity as a stealer, MassLogger targets an extensive list of applications with the intent of extracting log-in credentials and other sensitive information stored in them.

The targeted apps include (but are not limited to): browsers (Google Chrome, Mozilla Firefox, Opera, Yandex, Microsoft Edge [Chromium], Orbitum, Vivaldi, Brave); email clients (Outlook, Thunderbird, Foxmail); communication/messaging software (Discord, Pidgin, Telegram, QQ); VPN (Virtual Private Network) clients (NordVPN), and; FTP (File Transfer Protocol) clients (FileZilla).

Through stolen email accounts, cyber criminals can gain access and control over other accounts associated with them, and likewise with browsers that store log-in information.

Communication accounts (e.g. emails, messengers, social networking, social media, etc.) can be misused to demand loans from contacts/friends and/or to proliferate malware by sharing infectious files under the guise of the genuine owner. Should sensitive and/or compromising content be found in data storage accounts, it can be used for blackmail.

Accounts in some way connected to financial information (e.g. e-commerce, online money transfer, etc.) often store these details, which can then be used by criminals to make fraudulent transactions, online purchases, and so on. To summarize, MassLogger infections can lead to financial loss, serious privacy issues and identity theft.

Therefore, if it is suspected/known that this or other malware has already infected the system, it is crucial to use anti-virus software to remove it immediately.

Information-stealing malware examples

Sonbokli, Aria-body, 404 Keylogger and ProstoStealer are some examples of other malicious programs designed to steal information.

While the exact functionalities/features of these programs differ, as does the modus operandi of the individuals using them, the purpose is identical: to generate revenue for the cyber criminals responsible. Regardless of how malware operates or what it targets, these infections necessitate immediate removal to ensure device and user safety.

How did MassLogger infiltrate my computer?

Malware is distributed through various methods, most commonly via Trojans, spam campaigns, illegal activation ("cracking") tools, fake updaters and untrusted download sources. Trojans are malicious programs with a wide range of functionalities, which can include the capability to cause chain infections (i.e., download/installation of additional malware).

The term "spam campaign" describes a large scale operation, during which deceptive/scam emails are sent by the thousand. This mail contains the download links of infectious files, or has them attached to the message. Infectious files can be in various formats (e.g. PDF and Microsoft Office documents, archive and executable files, JavaScript, etc.).

When they are executed, run or otherwise opened, the infection process is initiated. Illegal activation tools ("cracks") can download/install malicious software, rather than activating your chosen products. Rogue updaters cause infections by exploiting weaknesses of outdated products and/or simply by installing malware, rather than the promised updates.

Dubious download channels such as unofficial and free file-hosting sites, Peer-to-Peer sharing networks (BitTorrent, Gnutella, eMule, etc.) and other third party downloaders can offer malicious programs disguised as, or bundled with, normal content.

How to avoid installation of malware

You are strongly advised against opening suspicious and/or irrelevant emails, especially those with any attachments or links found in them, as this can result in high-risk infection. All downloads must be done from official and verified sources.

It is also important to activate and update products with tools/functions provided by genuine developers, as opposed to illegal activation ("cracking") tools and third party updaters (they often spread malware). To protect device and user safety, it is paramount to have a reputable anti-virus/anti-spyware suite installed.

Furthermore, this software must be kept updated, used to run regular system scans, and to remove detected 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.

Screenshot of MassLogger process on Windows Task Manager ("NwjHbAE"):

Screenshot of MassLogger administration panel:

Screenshot of the website promoting MassLogger from which it can be purchased:

Example of a spam email spreading MassLogger virus:

Text presented within:

Subject: Cyber Security service offerings for Manufacturing Industries and RMG

Dear Sir

Greeting from PwC Bangladesh!!

I am Kazi Nazrul Islam on behalf of PwC in Bangladesh sending this letter to offer our Cybersecurity services to you. We are glad to offer you the cybersecurity services and hope to get an optimistic response from your side.

I am requesting you to kindly provide us with time for a short meeting through Webex/zoom or In-person for details discusses as per your convenient.

I am sure you would love to work with us and hence would love to render the necessary services.

Yours Truly.

Kazi Nazrul Islam

PwC | Sr.Consultant|One Cyber
Office: +8809612004000, Ext:4023 | Mobile: +8801817441511 | Fax: +88096120041000
Email: kazi.n.islam@pwc.com
PricewaterhouseCoopers Bangladesh Pvt Ltd
Laila Tower | 11th Floor | 8 Gulshan South Avenue | Gulshan 1 | Dhaka 1212 Bangladesh

hxxp://www.pwc.in/

The information transmitted, including any attachments, is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, re-transmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited, and all liability arising therefrom is disclaimed. If you received this in error, please contact the sender and delete the material from any computer.

Cyber criminals promoting MassLogger in a hacking forum (GIF):

Screenshot of yet another spam email used to spread MassLogger. The attachment is a .gz archive, which contains a malicious executable:

Text presented within:

Subject: Payment Schedule

The payment for the attached invoice will be made today 3/08/2020
please reconfirm the banking details to enable me proceed

Regards,
Accounts Department
mm ray

Yet another spam email used to spread MassLogger malware via attached malicious MS Word document:

Text presented within:

Subject: EIA ///// GSP INVOICE /// /F-1030

 

PAID INVOICE #595536

YOUR BEST PARTNER

Bill To:

-

Hi,

Transfer receipt attached for balance payment.

Please confirm receipt of funds with your accounts receivable.

Thanks & Regards,

Daisy Chiang (Ms.)

Remittance Address:

D.C. Medical Co., Ltd.

No. 600, Sec. 1, Dong Shan Rd.,Dong Shan, Yilan 26948, Taiwan.

Invoice Date: 10/15/2020
Previous paid Balance: $47,850.00
Current Balance Due: $39,150.00
Total Balance Due: $39,150.00

Contact Us

DA CHUNG MEDICAL CO., LTD.

No.600, Sec.1, Dong Shan Rd., Dong Shan Township, Yilan County, Taiwan

TEL: +886 3 959 4777
FAX: +886 3 9594707

www.dc-med.com.tw/en/

Yet another spam email used to spread MassLogger malware:

Text presented within:

Subject: URGENT

Good morning,

I tried  calling   your offline line yesterday, and earlier today, but couldn’t get through.
Please can you kind to check our attached request for an urgent quote

--

Livermore, CA 94551
Phone. 707.745.4030

Fax 951.343.3798
Toll Free 1-877-Powell9

CONFIDENTIALITY STATEMENT: This electronic message contains information from Powell & Associates Drafting LLC and may be confidential or privileged. The information is intended solely for the use of the individual(s) or entity(ies) named above. If you are not the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this message is prohibited. If you have received this e-mail in error, please notify us immediately by telephone at  (951) 352-3588 or by e-mail reply and delete this message and any attachments. To stop receiving emails please contact us and your information will removed from our records.

Example of a TNT-themed spam email used to spread MassLogger malware via attached malicious MS Word document:

Text presented within:

Subject: TNT Express courier notification

Dear Customer,

We have an arranged shipment for you with consignment number: 845553007644759 , but unfortunately we could not deliver to the provided address due to wrong addressing.

The shipment has been rescheduled to be delivered on 25th on this month.
We require that you provide your correct address in the attached shipping lable to enable us deliver accordingly.

Do you want to follow your package? Please check the shipping lable attached.

If you would like to find out about the many ways TNT helps you to track your shipment, or if you would like to know more about the services provided by TNT,
simply connect to  www.tnt.com  and select your location at any time.

--
This message has been checked by ESVA and is believed to be clean.

Screenshot of the attached malicious MS Word document:

Update March 2, 2021 - MassLogger is particularly active in Turkey, Spain, Ukraine, Brazil, Chile, United Kingdom, Germany, Poland, and the United States. This malware has significant obfuscation and anti-analysis abilities, including Windows Defender disabling, virtual machine and sandbox environment detection, anti-debugging, and so on.

Due to MassLogger's extensive obfuscation techniques, the malware is difficult to detect and analyze. In-depth information on these features can be found in an article by Anh Ho on decoded.avast.io website.

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

---

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

---

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 MassLogger malware, should I format my storage device to get rid of it?

No, MassLogger's removal does not necessitate formatting.

What are the biggest issues that MassLogger malware can cause?

The threats posed by a malicious program depend on its functionalities and the cyber criminals' aims. MassLogger is an information-stealing malware that has a variety of abilities designed to extract data. The primary dangers of such infections include - severe privacy issues, significant financial losses, and identity theft.

What is the purpose of MassLogger malware?

Most malware infections are geared towards generating revenue. However, attackers may also use this software to amuse themselves or to disrupt processes (e.g., websites, services, companies, organizations, etc.). Additionally, malware attacks can be motivated by personal grudges and even political/geopolitical reasons.

How did MassLogger malware infiltrate my computer?

Malware is primarily distributed through spam emails/messages, online scams, malvertising, untrustworthy download sources (e.g., unofficial and free file-hosting websites, P2P sharing networks, etc.), drive-by downloads, illegal program activation tools ("cracks"), and fake updates. Furthermore, some malicious programs can self-spread via local networks and removable storage devices such as external hard drives, USB flash drives, and others.

Will Combo Cleaner protect me from malware?

Yes, Combo Cleaner is designed to detect and remove threats. It is capable of eliminating practically all known malware infections. However, since high-end malicious programs usually hide deep within systems - therefore, running a complete system scan is essential for detection.