How to eliminate the FormBook malware from the operating system

What kind of malware is FormBook?

FormBook is a virus designed to steal personal data from victims' computers. Research shows that this malware is distributed using spam emails that contain malicious attachments. In addition, developers provide this virus as a 'service' - any aspiring cyber criminal can pay a subscription and gain access to the FormBook tool.

The list of victims is large, however, most FormBook infections have been detected in USA and South Korea.

Screenshot of a spam email distributing FormBook virus:

More about the FormBook malware

Following infiltration, FormBook starts monitoring computer activity and gathers data. This malware records keystrokes, takes screenshots, and grabs other information such as visited websites, clipboard data, saved logins/passwords, etc. The information often includes personal details (e.g., banking information) that FormBook's distributor can misuse to generate revenue.

Therefore, the presence of this malware can lead to significant financial losses and serious privacy issues. In addition, FormBook is capable of executing commands sent from remote Command and Control (C&C) servers.

For example, the commands are able to reboot and shutdown the system, download various files/archives and run/extract them, and so on (full list of features). In this way, criminals can perform remote tasks, leading to other high-risk computer infections or system corruption (e.g., criminals might download and execute ransomware). 

FormBook malware must be eliminated immediately. If you have recently opened suspicious email attachments and believe that your system is infected, use a legitimate anti-virus suite to perform a full system scan and eliminate all threats. In fact, you are strongly advised to have one installed and running. This will help to prevent further infections.

Similarities with other malware

FormBook shares similarities with a number of other malware infections such as Adwind. Most are developed by different cyber criminals and have slightly differing functionality. In general, however, they are more or less identical.

These viruses typically record user-system information, open backdoors for other high-risk malware to infiltrate the system, misuse system resources to mine cryptocurrency, or run other unwanted processes (e.g., Botnet).

The presence of these viruses might cause various problems including (but not limited to) system corruption, hardware damage, file loss, and privacy issues (e.g., identity theft).

How did FormBook install on my computer?

As mentioned above, FormBook is promoted using spam emails that contain messages relating to various business fields (e.g., engineering). These messages briefly describe the contents of malicious attachments (e.g., PDF file, MS Office document, or similar) and encourage users to open them.

Opening them, however, executes scripts that stealthily download and install malware. This distribution method is very popular amongst ransomware developers. Many regular users (especially those who know little about cyber security) are often tricked into downloading and opening such attachments.

How to avoid installation of malware?

The main reasons for computer infections are poor knowledge and careless behavior. If you want to prevent infections, be very cautious when browsing the Internet. We strongly advise you to think twice before opening email attachments - be sure that they are sent from trustworthy/recognizable addresses and that they are relevant.

Messages received via suspicious email addresses should be deleted immediately, without reading. Spam email is not the only way to proliferate malware. Therefore, be cautious when downloading/installing software. Download applications from official sources only, using direct download links.

Criminals monetize third party downloaders/installers by proliferating rogue apps, and thus, these tools should not be used. During downloading/installation, carefully analyze each step (especially "Custom/Advanced" settings) and opt-out of all additionally-included programs.

We also advise to keep installed applications up-to-date and, again, use a legitimate anti-virus/anti-spyware suite. Note, however, that criminals proliferate malware via fake updaters, so use implemented update functions only. As with download/installation tools, third party updaters should never be used. The key to computer safety is caution.

Another variant of spam email distributing FormBook:

List of FormBook's actions that can triggered using C&C server:

• Clear browser cookies
• Collect passwords and create a screenshot
• Download and execute file
• Download and unpack ZIP archive
• Launch a command via ShellExecute
• Reboot system
• Remove bot from host system
• Shutdown system
• Update bot on host system

Update May 18, 2020 - The outbreak of Coronavirus (COVID-19) has significantly affected the cyber world. Cybercriminals are taking advantage of the situation and attempting to spread malware in a variety of ways. One of the most popular methods is spam emails.

They send hundreds of thousands of Coronavirus-related emails containing malicious attachments to spread a variety of malware and FormBook is not an exception. You can read more about these spam emails in our "Coronavirus Email Virus" article.

Another spam email used to spread FormBook virus via attached malicious DMG file:

Text presented within:

Subject: PAYMENT

Dear Sir,

Kindly find the attached payment for our order via swift transfer for your reference.

Please provide us shipment details.

Thank you.

Best Regards,

Sales & Accounting Manager
--
WTL Italia SRL
Via San Piero, 94
56031 Bientina (PI)
Tel.0587 755355

Update October 26, 2020 - Cyber criminals have recently "rebranded" FormBook malware which is now named XLoader. The entire malware remains the same, only the name used in cyber criminal forums while selling this malware has changed.

Screenshot of yet another spam email used to spread FormBook malware (the attachment is a .r00 archive containing a malicious executable):

Text presented within:

Subject: Shipment Booking

 

Dear sir,

Please confirm delivery of the attached.

Best Regards
Mahmud Reaz
AGM (Customer Service)

Baro Bhuiyan, Apt.# 4C, House # 3B, Road # 49, Gulshan-2, Dhaka-1212, Bangladesh.
Tel : (88-02) 9861143 / 8823081/ 9880116 / 811294 Fax : (88-02) 9895141
Cell : +88 017 6666 5233
E-mail: csv-canada@crownlogisticsltd.com , / reaz-crown@accesstel.net
Web : www.crownlogisticsltd.com
Member of : BAFFA/FIATA/WCA FAMILY/CGLN/AWS/F-CUBE/WSA/GFK
WCA ID # 49329

Example of a malicious MS Excel document used to spread FormBook trojan:

Another example of a spam email used to spread FormBook malware:

Text presented within:

Subject: Notifica di pagamento anticipato del 30%

Buongiorno,

In allegato troverete una copia del bonifico bancario per il versamento del 30%.

Spero che la consegna sia puntuale.

Grazie.

Davide Fusetti

Adriatica SpA

Tel +39 0426 -

Fax +39 0426 -

k-fert.it - email: info@k-fert.it

before printing this email, think about the environment.

Notice:
This e-mail and any attachments thereto may contain information, which is confidential and/or protected by intellectual property rights, and are intended for the sole use of the recipient(s) named above. Any use of the information contained herein by persons other than the designated recipient(s) is prohibited. Although we attempt to sweep e-mail and attachments for viruses, it does not guarantee that either is virus-free and we accept no liability for any damage sustained as a result of viruses.

Yet another example of a spam email spreading FormBook:

Text presented within:

Good morning

Please find the attached proforma invoice

Kindly confirm that your bank details are correct before we proceed with payment today.

Awaits your swift response so we can proceed with the payment to your bank..

Hariani.PJ.
+97150 6591080 (whats app, WeChat, Line)
Gulf Ocean Electronics. LLC. ( Gulf Star )
P.O. Box. 103816, Bubai. ( UAE)
64, Bhanglaf Building
Al nakheel Road, Satellite Market,
Naif Road,
Deira,
Dubai (UAE)
Tel :- +9714 2220810
FAX :- +9714 2213448
Hariani . P . J. :- +97150 6591080
Email :- harianip@gulf-star.ae
Website :- www.gulf-star.com
MSN :- gulf_s@hotmail.com
WE CHAT :- Harianip
TRN: - 100022345100003

Yet another spam email used to spread FormBook malware via attached malicious executables:

Text presented within:

Subject: CARGO READINESS + INVOICE SUBMITTAL: PO DD-021-014 = OA 37220

Dear,

ATR processing just completed, please find attached:

Invoice

ATR

Certificate of origin.

We now await your shipping instructions.

Mit freundlichen Grüßen / Best regards,

Javier Urdiain
Auftragsabwicklung / Order Processing

T +49 (0) 8134 9341 15

E orders@rheonik.com
–––––––––––––––––––––––––––––– ––––––––––––––––––––––––––––––

**** Please see the latest news about our delivery times.    Click here.    ***

–––––––––––––––––––––––––––––– ––––––––––––––––––––––––––––––

Another example of a spam email spreading FormBook malware:

Text presented within:

Subject: Shipment Notification : 7048297463

 

DHL EXPRESS

Dear Customer,

Attached is the Original Shipping documents and BL as assigned to deliver to you.

Notification for shipment event group "Picked up" for 13th May 2022.

 AWB Number: 7048297463

Pickup date: 2022-05-13 14:44:09
Service: P
Pieces: 1
Cust. Ref:
Description:FULL SET DOCUMENTS.

Regards

Thank you for shipping with DHL Express!

Deutsche Post DHL - The Mail & Logistics Group.
2015 © DHL International GmbH. All rights reserved.

Terms & Conditions | Privacy system
DHL

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

---

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

---

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

---

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

FormBook can be removed by following the steps described in our article. It is unnecessary to format the storage device to eliminate FormBook malware.

What are the biggest issues that malware can cause?

Malware can be used to encrypt files, steal identities, and personal accounts, make fraudulent transactions (steal money), mine cryptocurrency, and other purposes. It depends on the type of malware (its capabilities).

What is the purpose of FormBook malware?

FormBook can record keystrokes, capture screenshots, steal information such as visited websites, clipboard data, saved logins/passwords, and more. Also, it can receive commands from C2 server and execute them. This feature can be used to inject additional malware and perform other actions on computer.

How did a malware infiltrate my computer?

It is known that FormBook is delivered via email. Cybercriminals send emails containing malicious attachments or links to trick recipients into executing FormBook. In other cases, malware can infect computers via malicious drive-by downloads, cracked software download pages, files downloaed from untrustworthy sources, etc.

Will Combo Cleaner protect me from malware?

Yes, Combo Cleaner scans the operating system and removes detected malware (it can detect almost all known malware). It is important to know that running a full system scan is a must when a computer is infected with high-end malware. Malware of this kind can hide deep in the system.