Clop Ransomware

Also Known As: Clop virus
Distribution: Low
Damage level: Severe

Clop ransomware removal instructions

What is Clop?

Clop is a ransomware-type virus discovered by Jakub Kroustek. This malware is designed to encrypt data and rename each file by appending the ".Clop" extension. For instance, "sample.jpg" is renamed to "sample.jpg.Clop". Following successful encryption, Clop generates a text file ("ClopReadMe.txt") and places a copy in every existing folder. The text file contains a ransom-demand message.

Generally, cyber criminals state that files are encrypted and that only they are capable of restoring them. Unfortunately, this information is accurate. It is currently unconfirmed whether Clop uses symmetric or asymmetric cryptography. In any case, each victim receives a unique decryption key which is necessary to restore data. All keys are stored on a remote server controlled by cyber criminals. Therefore, to receive a decryption key (or a decrypter with key embedded within), each victim must pay a ransom. They must first contact cyber criminals via one of email addresses provided. The cost is not specified in the text file and all details are provided via email, since this supposedly depends on how quickly the victim decides to make contact. In most cases, however, the cost fluctuates between $500 and $1500 in Bitcoins, Ethereum, Monero, DASH, or another cryptocurrency. Victims are also permitted to attach selected files (up to 5MB in total without containing any "useful information"), which are decrypted and returned as a 'guarantee' that cyber criminals can be trusted. No matter what the cost, do not agree to pay. Research shows that many ransomware developers ignore victims, once payments are submitted. Therefore, we strongly advise you to ignore all requests to contact these people or pay any ransoms. Unfortunately, there are no tools capable of cracking Clop encryption and restoring data free of charge. The only solution is to restore everything from a backup.

Screenshot of a message encouraging users to pay a ransom to decrypt their compromised data:

Clop decrypt instructions

The internet is full of ransomware-type viruses that share similarities with Clop, including Pluto, FileSlack, CryCipher, and Maoloa - these are just some examples from many. As with Clop, these viruses also encrypt data and make ransom demands. Ransomware-type infections typically have just two major differences: size of ransom and type of encryption algorithm used. Unfortunately, most employ algorithms that generate unique decryption keys. Therefore, unless the virus is not fully developed or has certain bugs/flaws (e.g., the key is hard-coded, stored locally, or similar), decrypting data without the involvement of developers (contacting these people is not recommended) is impossible. Therefore, we strongly advise you to maintain regular backups and to store them on a remote server (e.g., Cloud) or unplugged storage device (e.g., Flash drive, external hard drive, or similar). Backups stored locally are often encrypted together with regular software.

Threat Summary:
Name Clop virus
Threat Type Ransomware, Crypto Virus, Files locker
Encrypted Files Extension .clop
Ransom Demanding Message ClopReadMe.txt
Cyber Criminal Contact,,,
Antivirus detections Avast (Win32:Malware-gen), BitDefender (Trojan.GenericKD.41198091), ESET-NOD32 (a variant of Win32/GenKryptik.DFCB), Kaspersky (Trojan.Win32.Zenpak.eon), Full list of detections on VirusTotal
Symptoms Cannot open files stored on your computer, previously functional files now have a different extension (for example, my.docx.locked). A ransom demand message is displayed on your desktop. Cyber criminals demand payment of a ransom (usually in bitcoins) to unlock your files.
Additional Information Updated variants of Clop ransomware are capable of uninstalling present software, such as anti-virus suites.
Distribution methods Infected email attachments (macros), torrent websites, malicious ads.
Damage All files are encrypted and cannot be opened without paying a ransom. Additional password-stealing trojans and malware infections can be installed together with a ransomware infection.
Malware Removal (Windows)

To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Malwarebytes.
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How did ransomware infect my computer?

It is currently unknown exactly how developers proliferate Clop. In most cases, however, criminals use the following methods: trojans, fake software updaters, cracks, unofficial software download sources, and spam email campaigns. Trojans are malicious applications that, once infiltrated, inject additional malware into the system. Fake software updaters infect computers by exploiting outdated software bugs/flaws or simply downloading and installing malware rather than the promised updates. Cracks activate paid software free of charge, however, rather than gaining access to paid features, users often install viruses. Third party software download sources are used to present malicious executables as legitimate software, thereby tricking users into downloading and installing malware. Spam email campaigns proliferate viruses via malicious attachments. Criminals send hundreds of thousands of emails with deceptive messages encouraging users to open attached links/files. This, however, typically results in malware infection.

How to protect yourself from ransomware infections?

The key to computer safety is caution. Lack of knowledge and careless behavior are the main reasons for computer infections. Therefore, pay close attention when browsing the web and downloading, installing, and updating software. Think twice before opening email attachments. If the file/link does not concern you and the sender's email address seems suspicious/unrecognizable, do not open anything. Furthermore, download apps from official sources only, using direct download links. Third party downloaders/installers often proliferate malicious apps, and thus these tools should not be used. The same applies to software updates. It is important to keep installed applications (and operating systems) up-to-date, however, this should be achieved only through implemented functions or tools provided by the official developer. Never use software cracking tools for two reasons: 1) using pirated software is considered a cyber crime - you literally steal from software developers, and; 2) there is a high risk of computer infection, since these tools are often used to proliferate malware. Finally, have a reputable anti-virus/anti-spyware suite installed and running, since these tools can detect and eliminate malware before any damage is done. If your computer is already infected with Clop, we recommend running a scan with Malwarebytes for Windows to automatically eliminate this ransomware.

Text presented in Clop ransomware text file ("ClopReadMe.txt"):

Your network has been penetrated.
All files on each host in the network have been encrypted with a strong algorithm.
Backups were either encrypted or deleted or backup disks were formatted.
Shadow copies also removed, so F8 or any other methods may damage encrypted data but not recover.
We exclusively have decryption software for your situation
No decryption software is available in the public.
DO NOT RESET OR SHUTDOWN ñ files may be damaged.
DO NOT RENAME OR MOVE the encrypted and readme files.
DO NOT DELETE readme files.
This may lead to the impossibility of recovery of the certain files.
Photorec, RannohDecryptor etc. repair tools are useless and can destroy your files irreversibly.
If you want to restore your files write to emails (contacts are at the bottom of the sheet) and attach 2-3 encrypted files
(Less than 5 Mb each, non-archived and your files should not contain valuable information
(Databases, backups, large excel sheets, etc.)).
You will receive decrypted samples and our conditions how to get the decoder.
Your warranty - decrypted samples.
Do not rename encrypted files.
Do not try to decrypt your data using third party software.
We don`t need your files and your information.
But after 2 weeks all your files and keys will be deleted automatically.
Contact emails:
The final price depends on how fast you write to us.

Screenshot of files encrypted by Clop (".Clop" extension):

Files encrypted by Clop

Update November 22, 2019 - Cyber criminals have recently released an updated variant of Clop ransomware which is now capable of uninstalling various applications, such as anti-virus suites.

Screenshot of updated Clop ransomware's text file ("ClopReadMe.txt"):

Updated Clop ransomware ransom note

Text presented within this file:

All files on each host in the network have been encrypted with a strong algorithm.


Backups were neither encrypted or deleted or backup disks were formatted
Shadow copies also removed, so F8 or any other methods may damage encrypted data but not recover
If you want to restore your files writ to emails (contacts are at the bottom of the sheet) and attach 3-5 encrypted files
(Less than 5 Mb each, non-archived and your files should not contain valuable information
(Databases, backups, large excel sheets, etc.)).
You will receive decrypted samples.


Message this information to company's CEO, unlocking of 1 computer only is impossible, only whole network.


Your warranty- decrypted samples.
Do not rename encrypted files.
Do not try to decrypt your data using third party software.
We don't need your files and your information.



Update March 24, 2020 - The developers of Clop ransomware have recently released a website that will host data of victims that disagreed to pay the ransom. This means that all the threats to leak stolen data are real.

Clop ransomware removal:

Instant automatic malware removal: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Malwarebytes is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:
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Quick menu:

Step 1

Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.

Safe Mode with Networking

Video showing how to start Windows 7 in "Safe Mode with Networking":

Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button. Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.

Windows 8 Safe Mode with networking

Video showing how to start Windows 8 in "Safe Mode with Networking":

Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click "Restart" while holding "Shift" button on your keyboard. In the "choose an option" window click on the "Troubleshoot", next select "Advanced options". In the advanced options menu select "Startup Settings" and click on the "Restart" button. In the following window you should click the "F5" button on your keyboard. This will restart your operating system in safe mode with networking.

windows 10 safe mode with networking

Video showing how to start Windows 10 in "Safe Mode with Networking":

Step 2

Log in to the account infected with the Clop virus. Start your Internet browser and download a legitimate anti-spyware program. Update the anti-spyware software and start a full system scan. Remove all entries detected.

If you cannot start your computer in Safe Mode with Networking, try performing a System Restore.

Video showing how to remove ransomware virus using "Safe Mode with Command Prompt" and "System Restore":

1. During your computer start process, press the F8 key on your keyboard multiple times until the Windows Advanced Options menu appears, and then select Safe Mode with Command Prompt from the list and press ENTER.

Boot your computer in Safe Mode with Command Prompt

2. When Command Prompt mode loads, enter the following line: cd restore and press ENTER.

system restore using command prompt type cd restore

3. Next, type this line: rstrui.exe and press ENTER.

system restore using command prompt rstrui.exe

4. In the opened window, click "Next".

restore system files and settings

5. Select one of the available Restore Points and click "Next" (this will restore your computer system to an earlier time and date, prior to the Clop ransomware virus infiltrating your PC).

select a restore point

6. In the opened window, click "Yes".

run system restore

7. After restoring your computer to a previous date, download and scan your PC with recommended malware removal software to eliminate any remaining Clop ransomware files.

To restore individual files encrypted by this ransomware, try using Windows Previous Versions feature. This method is only effective if the System Restore function was enabled on an infected operating system. Note that some variants of Clop are known to remove Shadow Volume Copies of the files, so this method may not work on all computers.

To restore a file, right-click over it, go into Properties, and select the Previous Versions tab. If the relevant file has a Restore Point, select it and click the "Restore" button.

Restoring files encrypted by CryptoDefense

If you cannot start your computer in Safe Mode with Networking (or with Command Prompt), boot your computer using a rescue disk. Some variants of ransomware disable Safe Mode making its removal complicated. For this step, you require access to another computer.

To regain control of the files encrypted by Clop, you can also try using a program called Shadow Explorer. More information on how to use this program is available here.

shadow explorer screenshot

To protect your computer from file encryption ransomware such as this, use reputable antivirus and anti-spyware programs. As an extra protection method, you can use programs called HitmanPro.Alert and EasySync CryptoMonitor, which artificially implant group policy objects into the registry to block rogue programs such as Clop ransomware.

Note that Windows 10 Fall Creators Update includes a "Controlled Folder Access" feature that blocks ransomware attempts to encrypt your files. By default, this feature automatically protects files stored in the Documents, Pictures, Videos, Music, Favorites as well as Desktop folders.

Controll Folder Access

Windows 10 users should install this update to protect their data from ransomware attacks. Here is more information on how to get this update and add an additional protection layer from ransomware infections.

HitmanPro.Alert CryptoGuard - detects encryption of files and neutralises any attempts without need for user-intervention:

hitmanproalert ransomware prevention application

Malwarebytes Anti-Ransomware Beta uses advanced proactive technology that monitors ransomware activity and terminates it immediately - before reaching users' files:

malwarebytes anti-ransomware

  • The best way to avoid damage from ransomware infections is to maintain regular up-to-date backups. More information on online backup solutions and data recovery software Here.

Other tools known to remove Clop ransomware:

About the author:

Tomas Meskauskas

Tomas Meskauskas - expert security researcher, professional malware analyst.

I am passionate about computer security and technology. I have an experience of over 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an author and editor for since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats. Contact Tomas Meskauskas.

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Removal Instructions in other languages
Malware activity

Global malware activity level today:

Medium threat activity

Increased attack rate of infections detected within the last 24 hours.

QR Code
Clop virus QR code
A QR code (Quick Response Code) is a machine-readable code which stores URLs and other information. This code can be read using a camera on a smartphone or a tablet. Scan this QR code to have an easy access removal guide of Clop virus on your mobile device.
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