Remove Cosd ransomware (Easy Removal Guide) - Recovery Instructions Included

removal by Ugnius Kiguolis - - | Type: Ransomware

Cosd virus Removal Guide

What is Cosd ransomware?

Cosd ransomware – a file-locker virus developed for direct blackmailing purposes

Cosd ransomwareCosd ransomware is the 279th version in the Djvu family that focuses on random extension forming.

Cosd ransomware is a computer infection that encrypts data on a victim's computer and demands to purchase a decryption tool required to regain access to said files. It also renames encrypted data by appending .cosd extension to all original filenames. All files are encoded with a military-grade RSA 2048 coding algorithm and might be indecipherable without the intervention of the cybercriminals. Although contacting them or paying the ransom is highly recommended.

Following successful encryption, ransomware generates a ransom note, titled _readme.txt, and places it on the desktop so the victims would find it easily. The note contains instructions and persuasion techniques to convince victims to contact their assailants via,, emails, and purchase their decryption tool. Its price varies depending on how quickly victims establish contact – if that's done within 72 hours, the price is $490. If they're not hasty, the price will be doubled to $980.

Cosd virus derives from the infamous Djvu ransomware family that's been threatening regular computer users around the world since December 2018. This is the 279th version of the particular threat. Each week new variations, such as the Pola virus, Wbxd virus, Coos virus, are created and spread on the internet. Therefore, companies like Emisoft have dedicated their time to fight these cybercriminals by creating free decryptors for their victims. Although not all strains are decryptable, you can still download their tool and give it a go.

You have alternate options like data recovery tools or functions of the OS, but the best way to repair those files – data backups from different devices. This is possible after the virus termination. This article contains a summary of the culprit, its delivery techniques, and of course – removal guide. Down below, you can find all the options that are possibly useful for the encoded file recovery.

name Cosd ransomware
Type Cryptovirus, file-locker
Family Djvu/STOP ransomware
Appended file extension Non-system files (pics, documents, archives, etc.) are appended with .cosd extension
Ransom note _readme.txt can be found on the desktop of the infected machine
Ransom amount $490/$980
Criminal contact details Two emails are provided to establish contact with the assailants:,
Distribution Spam emails, file-sharing platforms, especially torrent sites
Malware removal Trustworthy anti-malware tools should be used to eliminate any kind of malware fully. You can remove Cosd ransomware itself with the help of the guide below and professional AV tools and then rely on data recovery
System repair Various system files and settings get corrupted and damaged during the encryption. Victims should use the powerful ReimageIntego system repair tool to fix any system irregularities

Almost all ransomware-type infections leave ransom notes after encrypting personal data, such as documents, archives, databases, etc. The same goes for Cosd ransomware virus. It creates a text file named _readme.txt and leaves it on the desktop. Within it, cybercriminals reassure their victims that their files can be retrieved if they pay the requested amount of money. Although the preferred payment method isn't specified, we can speculate that criminals will ask for cryptocurrency Bitcoins.

To convince users to meet their demands, cybercriminals use many techniques. They offer free decryption of a single file from the infected machine and provide a link to a video where the said decryptor can be seen in action. Moreover, they offer a 50% discount for the ones who contact them within 72 hours. To put it in other words, Cosd creators try to push victims into making rash decisions.

The whole message in the _readme.txt file reads:


Don't worry, you can return all your files!
All your files like pictures, databases, documents and other important are encrypted with strongest encryption and unique key.
The only method of recovering files is to purchase decrypt tool and unique key for you.
This software will decrypt all your encrypted files.
What guarantees you have?
You can send one of your encrypted file from your PC and we decrypt it for free.
But we can decrypt only 1 file for free. File must not contain valuable information.
You can get and look video overview decrypt tool:
Price of private key and decrypt software is $980.
Discount 50% available if you contact us first 72 hours, that's price for you is $490.
Please note that you'll never restore your data without payment.
Check your e-mail “Spam” or “Junk” folder if you don't get answer more than 6 hours.

To get this software you need write on our e-mail:

Reserve e-mail address to contact us:

Your personal ID:

Needless to say that we stand on the same side with the FBI,[1] other authorities, and cybersecurity specialists when it comes to contacting the criminals and paying them. Ransomware victims should never do that, as that's the only way to stop this malicious software from spreading. Criminals go where the money goes. If there's no money in ransomware, they will seize to develop it.

Cosd ransomware virusCosd ransomware - a cryptovirus that makes demands scary enough, so people pay for the alleged decryption tool.

Therefore, our cybersecurity team has assembled the best options to remove Cosd ransomware. First of all, if you had an anti-malware solution installed on your device before it was infected, it could mean two things – either its virus database was out of date, or it's incapable of stopping serious malware.

Our team suggests using trustworthy anti-malware tools like SpyHunter 5Combo Cleaner or Malwarebytes that will not only successfully accomplish Cosd ransomware removal but protect your devices from such hazards in the future. Run a full threat scan and eliminate any and all suspicious files that it suggests to do so.

Now that the Cosd file virus is taken care of, it's time for the computer system itself. Ransomware, and especially the ones from Djvu lineage, do extensive damage to key system files. Thus they need attention, or your device will function improperly. If you down have powerful system repair tools, experts[2] recommend using the ReimageIntego tune-up tool or similar software. When these steps are completed, you're safe to restore your data from backups and enjoy your device anew.

File-sharing platforms – the most popular Djvu ransomware delivery technique

Ransomware attacks have been around for decades[3] and if people don't stop paying their assailants – they won't go anywhere anytime soon. There are many file-locking virus versions created, and they can be spread using different distribution techniques, including RDP attacks, spam emails, deceptive ads, and so on.

Cosd file virusCosd ransomware is the virus that marks encoded files using .cosd appendix.

Our cybersecurity team has finished research showing that most Djvu family ransomware is hidden in (thus delivered through) file-sharing platforms, especially most-visited torrent portals. Cybercriminals realized that they could exploit the weakness of people who want to cheat the system by getting licensed, commercial software for free.

Hackers used catchy names to camouflage their creations and attract gullible people. Few examples of how ransomware was disguised as:

  • cracks for the latest, most popular games,
  • unlocked expensive applications,
  • cracks for commercial software,
  • game cheat codes.

So if you value your files, security, money, and privacy, we advise you to refrain from using torrent sites altogether. Ransomware could be hidden in practically any torrent. Support your beloved, desired software developers by purchasing their products from them or official distributors.

Detailed guidelines for Cosd ransomware virus removal from infected Windows devices

Suppose you've spotted any indications such as _readme.txt ransom note, or .cosd extension appended to your files, then your anti-malware software failed you, and your device is infected with Djvu ransomware. The good news is that that's not the end of the world as this cryptovirus can be removed, and there's even a possibility to restore your files (if you didn't keep backups).

We're thankful that you chose us to help you remove Cosd ransomware. First of all, you should try the decryption software offered by Emisoft, as they specialize in helping people after Djvu family ransomware attacks. Keep in mind that not all cryptoviruses from this lineage are decyphered, so the decryptor might not be right for you. If it doesn't work, then export all encrypted files to an offline storage device and check back with us later as we update our readers with the latest news.

When that's done, you will need anti-malware software to proceed with removal. If you don't own one, we recommend getting professional tools such as SpyHunter 5Combo Cleaner or Malwarebytes. Launch it and scan the entire computer system. Remove any suspicious files. If the file-locker virus disabled anti-malware software, then reboot your device and start it in Safe Mode with Networking and launch the security tool then. If you're unsure how to access this mode, please scroll down as we display the full instructions below.

Cosd ransomware virus, like most of its family members, makes various changes to system files and settings. That could impede normal system behavior by disabling anti-malware tools, preventing from visiting security-related websites, and many other issues. To restore all these changes and get your system back on its feet, we advise using the ReimageIntego system repair tool.

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Reimage Happiness
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Compatible with Microsoft Windows Compatible with macOS
What to do if failed?
If you failed to remove virus damage using Reimage Intego, submit a question to our support team and provide as much details as possible.
Reimage Intego has a free limited scanner. Reimage Intego offers more through scan when you purchase its full version. When free scanner detects issues, you can fix them using free manual repairs or you can decide to purchase the full version in order to fix them automatically.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Reimage, try running SpyHunter 5.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Intego, try running Combo Cleaner.

Getting rid of Cosd virus. Follow these steps

Manual Cosd removal using Safe Mode

Important! →
Manual removal guide might be too complicated for regular computer users. It requires advanced IT knowledge to be performed correctly (if vital system files are removed or damaged, it might result in full Windows compromise), and it also might take hours to complete. Therefore, we highly advise using the automatic method provided above instead.

Step 1. Access Safe Mode with Networking

Manual malware removal should be best performed in the Safe Mode environment. 

Windows 7 / Vista / XP

  1. Click Start > Shutdown > Restart > OK.
  2. When your computer becomes active, start pressing F8 button (if that does not work, try F2, F12, Del, etc. – it all depends on your motherboard model) multiple times until you see the Advanced Boot Options window.
  3. Select Safe Mode with Networking from the list.Windows 7/XP

Windows 10 / Windows 8

  1. Right-click on Start button and select Settings.
  2. Scroll down to pick Update & Security.
    Update and security
  3. On the left side of the window, pick Recovery.
  4. Now scroll down to find Advanced Startup section.
  5. Click Restart now.
  6. Select Troubleshoot.Choose an option
  7. Go to Advanced options.Advanced options
  8. Select Startup Settings.Startup settings
  9. Press Restart.
  10. Now press 5 or click 5) Enable Safe Mode with Networking.Enable safe mode

Step 2. Shut down suspicious processes

Windows Task Manager is a useful tool that shows all the processes running in the background. If malware is running a process, you need to shut it down:

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Click on More details.
    Open task manager
  3. Scroll down to Background processes section, and look for anything suspicious.
  4. Right-click and select Open file location.
    Open file location
  5. Go back to the process, right-click and pick End Task.
    End task
  6. Delete the contents of the malicious folder.

Step 3. Check program Startup

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Go to Startup tab.
  3. Right-click on the suspicious program and pick Disable.

Step 4. Delete virus files

Malware-related files can be found in various places within your computer. Here are instructions that could help you find them:

  1. Type in Disk Cleanup in Windows search and press Enter.
    Disk cleanup
  2. Select the drive you want to clean (C: is your main drive by default and is likely to be the one that has malicious files in).
  3. Scroll through the Files to delete list and select the following:

    Temporary Internet Files
    Recycle Bin
    Temporary files

  4. Pick Clean up system files.
    Delete temp files
  5. You can also look for other malicious files hidden in the following folders (type these entries in Windows Search and press Enter):


After you are finished, reboot the PC in normal mode.

Remove Cosd using System Restore

Using System Restore for threat elimination

  • Step 1: Reboot your computer to Safe Mode with Command Prompt
    Windows 7 / Vista / XP
    1. Click Start Shutdown Restart OK.
    2. When your computer becomes active, start pressing F8 multiple times until you see the Advanced Boot Options window.
    3. Select Command Prompt from the list Select 'Safe Mode with Command Prompt'

    Windows 10 / Windows 8
    1. Press the Power button at the Windows login screen. Now press and hold Shift, which is on your keyboard, and click Restart..
    2. Now select Troubleshoot Advanced options Startup Settings and finally press Restart.
    3. Once your computer becomes active, select Enable Safe Mode with Command Prompt in Startup Settings window. Select 'Enable Safe Mode with Command Prompt'
  • Step 2: Restore your system files and settings
    1. Once the Command Prompt window shows up, enter cd restore and click Enter. Enter 'cd restore' without quotes and press 'Enter'
    2. Now type rstrui.exe and press Enter again.. Enter 'rstrui.exe' without quotes and press 'Enter'
    3. When a new window shows up, click Next and select your restore point that is prior the infiltration of Cosd. After doing that, click Next. When 'System Restore' window shows up, select 'Next' Select your restore point and click 'Next'
    4. Now click Yes to start system restore. Click 'Yes' and start system restore
    Once you restore your system to a previous date, download and scan your computer with ReimageIntego and make sure that Cosd removal is performed successfully.

Bonus: Recover your data

Guide which is presented above is supposed to help you remove Cosd from your computer. To recover your encrypted files, we recommend using a detailed guide prepared by security experts.

If your files are encrypted by Cosd, you can use several methods to restore them:

Restore .cosd extension files with Data Recovery Pro

Data Recovery Pro might be able to restore some of your encrypted files on the infected machine.

  • Download Data Recovery Pro;
  • Follow the steps of Data Recovery Setup and install the program on your computer;
  • Launch it and scan your computer for files encrypted by Cosd ransomware;
  • Restore them.

Restoring files with Windows Previous Version

With this feature, victims of ransomware attacks might be able to restore files individually, i.e., one at a time.

  • Find an encrypted file you need to restore and right-click on it;
  • Select “Properties” and go to “Previous versions” tab;
  • Here, check each of available copies of the file in “Folder versions”. You should select the version you want to recover and click “Restore”.

Recover .cosd extension files with Shadow Explorer

This open-source software restores files from Shadow Volume Copies. If they weren't deleted during the encryption, then you might be in luck.

  • Download Shadow Explorer (;
  • Follow a Shadow Explorer Setup Wizard and install this application on your computer;
  • Launch the program and go through the drop down menu on the top left corner to select the disk of your encrypted data. Check what folders are there;
  • Right-click on the folder you want to restore and select “Export”. You can also select where you want it to be stored.

Possible decryption methods

The decryption tool that's made by Emisoft might help decipher files encrypted by the culprit of this article. But there's no guarantee as this file-locker is brand new. 

Finally, you should always think about the protection of crypto-ransomwares. In order to protect your computer from Cosd and other ransomwares, use a reputable anti-spyware, such as ReimageIntego, SpyHunter 5Combo Cleaner or Malwarebytes

How to prevent from getting Cosd ransomware

Protect your privacy – employ a VPN

There are several ways how to make your online time more private – you can access an incognito tab. However, there is no secret that even in this mode, you are tracked for advertising purposes. There is a way to add an extra layer of protection and create a completely anonymous web browsing practice with the help of Private Internet Access VPN. This software reroutes traffic through different servers, thus leaving your IP address and geolocation in disguise. Besides, it is based on a strict no-log policy, meaning that no data will be recorded, leaked, and available for both first and third parties. The combination of a secure web browser and Private Internet Access VPN will let you browse the Internet without a feeling of being spied or targeted by criminals. 

No backups? No problem. Use a data recovery tool

If you wonder how data loss can occur, you should not look any further for answers – human errors, malware attacks, hardware failures, power cuts, natural disasters, or even simple negligence. In some cases, lost files are extremely important, and many straight out panic when such an unfortunate course of events happen. Due to this, you should always ensure that you prepare proper data backups on a regular basis.

If you were caught by surprise and did not have any backups to restore your files from, not everything is lost. Data Recovery Pro is one of the leading file recovery solutions you can find on the market – it is likely to restore even lost emails or data located on an external device.

About the author
Ugnius Kiguolis
Ugnius Kiguolis - The mastermind

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