Cosd Virus [Cosd Ransomware] Removal (+Decrypt .cosd files)

All your files got .cosd extension at the end? Are you not able to access any of your data? Your computer is infected by Cosd File encrypting malware which is the latest variant of STOP/DJVU Ransomware. It has encrypted all your files and forcing you to pay ransom money for unlocking of your data. Well don’t panic, this guide is aimed to help you remove this nasty virus and recover your files.

SpyHunter 5 Anti-Malware

Threats like Cosd keep getting back on PC, if all associated files are not removed. So you are advised to use a powerful Malware Removal Tool to run a thorough scan of your PC and delete all threats at once.

Special Offer SpyHunter 5 Anti-Malware allows you, subject to a 48-hour waiting period, one remediation and removal for results found. Read SpyHunter 5 Review, EULA and Privacy Policy

Cosd ransomware is a STOP/DJVU variant

Cosd is a recently detected ransomware-type malware infection that encrypt files on victim’s computer. This nasty file-encrypting virus belongs to the notorious STOP/DJVU Ransomware family. It is set to corrupt files on the system which it has infected. It uses a powerful encryption algorithm to encode users’ files and after people cannot access their data. Encrypted files are marked with the “.Cosd” file extension which its name. File locked by this malware has a custom decryption key which is needed to unlock the data. Creators of .Cosd File Virus demand ransom money to give that key and restore files upon payment.

Once this .Cosd virus encrypt your files, from that moment forward you can no longer access any of your data. A ransom note named “_Readme.txt” will be placed on your computer (almost in every folder) to remind you of encryption and demand ransom money. This note contains a text message in which hackers ask users to contact by writing on helpmanager@mail.ch or restoremanager@airmail.cc email addresses. They also ask users to pay a hefty ransom amount of $480 to $980 USD in Bitcoins for decryption tool.

What is Cosd Ransomware

Cosd File virus is actually a strain of an older malware STOP/Djvu which is a cryptovirus. Cybercriminals who created this malware keep releasing new variants on regular interval to avoid breaking of their codes. Currently there are more than 270 different versions of this nasty malware are released. Every time a new variant is launched, the decryption codes get changed, so chances of creating any Universal decryptor which work for all variants are none.

Most of the victims of Cosd virus reported that their computer got infected after browsing untrustworthy sites like torrent in search of pirated programs. Cracked software usually contains some types of Trojan spoof the license key authentication process. These Trojans can be easily used to distribute malware like .Cosd file virus. Users normally download such filthy programs on their own and also stop their antivirus protection to install them. Once installed, this Cosd virus instantly start then encryption process and targets important files, like videos, images, documents, audio, and etc. This virus soon take full control of victim’s computer and all the personal files, then it leaves the ransom note with instructions for paying the extortion fees.

Warning : Do not pay the ransom to the attackers, you may get cheated. Try the suggested malware removal and file recovery methods first explained in the tutorial.

What this Cosd virus Do to your files

As we told you, Cosd is file-encrypting malware and it uses very advanced RSA and AES encryption algorithm to lock files of infected PC. If you don’t know what encryption is, then you you should understand that is a type of protection for digital in which files can locked by a using unique private decryption key generated by computer through random digits. There is no way to duplicate that key and thus it is simply not possible to unlock files without knowing the key.

Cosd File Virus Ransomware

Cosd virus uses this technique to lock files on your computer knowing that you will have no option that paying ransom money to get your files back. After successful encryption of your files, it adds its “.Cosd” extension. For an example if a file name “myphoto.jpg” get encoded, then will changed into “myphoto.jpg.Cosd” and you cannot open it without decryption code. So this is the method used by hackers to blackmail innocent users and force them into paying hefty ransom money.

Contents of the “_Readme.txt” ransom note left behind

Cosd Ransomware leaves the ransom note to explains its victims that their files are only locked. They can restore their files in return for fee which is to be paid in Bitcoins. It notifies users that all their photos, databases, documents and other important files. Hackers behind this .Cosd virus also offers free decryption of 1 files as proof that they can restore all the files to previous version. They have set a price for the decryption key of $490 USB in Bitcoins if users contact them and pay the ransom within 72 hours. If not the price is likely to get doubled which is $980 USD. Contacts details of hackers are also provided in the ransom note.

Ransom note left by the virus consist following text message :


Don’t worry, you can return all your files!
All your files like photos, 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:

Do Not pay Ransom money to hackers

As many security experts advise, you should not pay any money to cybercriminals. The main motive of hackers is to make illegal profit and they might never give you decryption tool. In many cases we have observed that and many victims reported us that hackers stop all communications after getting the money. Since hackers demand ransom money in Bitcoins, so there is no way to find who you are paying. Cosd ransomware works with single motive of blackmailing users and forcing them to pay money. Providing decryption key is solely depend on evil hackers which you cannot trust. We suggest you to remove .Cosd File Virus completely from your system and then try alternative ways to restore your encrypted files like backup copies or using data recovery software.

Cosd Ransomware : Threat Analysis

Name Cosd
Type Ransomware, File-Encrypting virus
Family STOP/DJVU Ransomware
Extension .Cosd
Threat Level High (Encrypt all your data and Restrict access to your files).
Symptoms Victims cannot access any files on their PC and find Ransom note asking for money.
Damage Cosd Ransomware will  encrypt your data by adding .Cosd extension to file names and demand ransom money for decryption key
Ransom Note _Readme.txt
Ransom Amount $490 USD to $980 USD
Distribution It is mainly distributed through spam emails, bundled freeware, porn or torrent sites.
Removal Download SpyHunter 5 Anti-Malware
File Recovery Download Data Recovery Software Now

How your PC got infected by Cosd

It is very important to understand how your system got infected by this virus so that you can protect PC in future. First thing we would like to mention is, the use of cracked or pirated software on your system can bring .Cosd File Virus on your system. Pirated copy of Windows is also vulnerable to threats because it uses KMSPICO for the activation which is a well known virus and malware distributor. Clicking on unknown ads, pop-up, banners, push notification in search of free application also redirect users on suspicious websites which may host malicious codes. Most of the freeware programs contains malicious attachments which can be installed silently without users’ permission. Browsing to porn sites or sharing files on unsafe network can also bring this malware on your PC.

Cosd ransomware virus removal tips

Cosd ransomware is a not common threat and thus it might not be so easy to get rid of this infection. You must seek professional help for the removal of this nasty malware from your system. We advise to use both manual and automatic methods to ensure the safe and permanent elimination of this threat. For that, you will need to use a Powerful Anti-Malware Tool which find and remove this infection at once. We have created a details guide with step-by-step instructions to help you in the removal process of .Cosd File Virus.

Anti-malware Tool can easily detect and remove this infection from your and can also block this malware or similar threats in future. You need to run a thorough scan of your PC and remove all the files and elements related to this Cosd ransomware virus. Do not try to format or reinstall your Windows because after you can never restore your files.

Once the removal of this infection then you can create a backup of all the encrypted files and store on any external hard drive of cloud drive. Then if you have any backup of your previous files then you can use them to restore your files. If you don’t have backup then you can wait for the decryption tool or try a good Data Recovery Software to help you recover your files.

Automatic Cosd Removal Guide

As you already know that, Cosd Virus is a notorious and cunning malware which is not hard to remove easily by any user through manual means. This virus can keep coming back on the infected computer through files and shortcuts or settings that it has already created on your machine. Removing all those at once is the only way to get rid of this infection and stop it from getting on your system ever again.

So the best way to remove Cosd effectively is to use a powerful Automatic Removal Tool and save your time and efforts. This software is a well trusted and very powerful anti-malware program which can detect all hidden threats like Trojan, Ransomware, Worms, Spyware, Rootkits and many others. It also provides 24X7 customer support and one-on-one Spyware HelpDesk support for Custom Malware removal. Advanced System Guard feature detects and remove threats in real time. It has a very User-Friendly Interface and regular Malware updates make it most effective against latest malware attacks.

How SpyHunter 5 Anti-Malware Works

  • First you need to click on below download button to get the software.

Geek’s Recommendation

Some time threats like Cosd keep getting back on the machine, if all associated files are not removed. So you are advised to use a powerful Malware Removal Tool to run a thorough scan of your PC and delete all threats at once.

SpyHunter 5 Anti-Malware allows you, subject to a 48-hour waiting period, one remediation and removal for results found. Read SpyHunter 5 Review, EULA and Privacy Policy

  • Then double-click on installer you downloaded to install the program.

double clickAllow access

  • Launch Anti-Malware application and Start Scan Now of your PC.

Scan for Cosd

  • Software will scan your PC all hidden threats and viruses on your system.

Scan for Cosd

  • Click on Next button to see results and delete Cosd and other threats.

Remove Cosd

How To Recover Your Encrypted Files

Now all your files got encrypted by .Cosd Virus then you need to recover your data without paying ransom money to hackers. If your files are important then you must have created backup and you can use that backup to recover your files. If you don’t have backup or this virus has encrypted your backup files, then you are left to seek the professional help.

We recommend you to use a powerful data recovery software to restore your files encrypted .Cosd File Virus. It is risk free and smart way. You can just download the free version and scan your PC for files. There is a high probability that it can recover most of your files in a fraction of amount what hackers are demanding. It is also needless to say that paying hackers will only motivate hackers to carry out more attacks.

  • First you need to download Data Recovery software on your PC.

Download Data Recovery Software Now

  • Install the program, launch it then select Data type to recover and click Next button.

select Data type

  • Select the location from where you want to recover data and click Scan button.

Select location

  • After scan, software will list all files, select them and click Recover button.

Recover Cosd encrypted files

Manual Cosd Removal Guide

tip Before you start Manual Removal
Please Bookmark This Page by pressing {ctrl+D} button or print it out on a paper before you start the Manual Removal because you may need to restart your PC or browser.) Attention! For safety of your system, please confirm few things before you begin Manual Removal of Cosd Ransomware:
  1. You have done this before, means you have experience for removing virus manually;
  2. That you know your way around PC and  all necessary process and applications;
  3. You know about Registry entry and Serious repercussions of any mistake;
  4. Make sure you can reverse any mistake made during .Cosd Virus manual removal.

If you don’t attain any of  the above standards, then manual removal could be a very risky idea. It is most likely best for you to use Automatic Malware Removal Tool to find and delete Cosd Virus, which is totally securely and efficient method.

SpyHunter 5 Anti-Malware allows you, subject to a 48-hour waiting period, one remediation and removal for results found. Read SpyHunter 5 Review, EULA and Privacy Policy


Start PC in safe mode with networking

  • Press Windows Key + R buttons together on keyboard.
  • Type msconfig in the Run Box then click OK button.
  • Click on Boot tab then System configuration window will appear.
  • Choose Safe Boot, check network box, Click Apply and press OK button.

Safe boot

Kill Malicious Process From Task Manager

  • Press Windows Key + R buttons together on keyboard.
  • Type taskmgr in Run Box and then click OK button.
  • Find Cosd related or any malicious process.
  • Now right click on it then click End process.

Stop Cosd related task

How To Uninstall Cosd from Windows PC

  • First of all Press Windows Key + R buttons together.
  • Type appwiz.cpl in the Run Box and then click OK button.
  • Now Programs and Features windows will appear on screen.
  • Find and remove all Cosd related or malicious programs.

Remove Cosd

Warning : Do not play with Windows registry, host file of restore options if you don’t have previous experience with. Removing wrong files may break your system entirely. So if you are not sure, then stick to the Automatic Malware Removal option. SpyHunter 5 Anti-Malware allows you, subject to a 48-hour waiting period, one remediation and removal for results found. Read SpyHunter 5 Review, EULA and Privacy Policy

Remove Virus related Windows Registry entries

  • Press Windows Key + R buttons together on keyboard.
  • Type taskmgr in Run Box and then click OK button.
  • Registry Editor will open, then press CTRL +F buttons together.
  • Now type Cosd and then click on Find Next button.
  • Find all the related entries and delete them one by one

Remove Cosd related registry

Delete Virus related files form your PC

When a threat get on to a PC, it most likely create some files at different locations on the system. These files are used to perform specific action and also help malware in getting back to the computer once its removed. So you just need to find also delete all those files associated with this .Cosd File Virus. For that follow the below instruction :

  • Press Windows Key + R buttons together on keyboard
  • Type each of the following in Run Box and press OK button
  1. %AppData%
  2. %LocalAppData%
  3. %ProgramData%
  4. %WinDir%
  5. %Temp%

For the first four option, look for any recent folder related to .Cosd File Virus and remove them. For the Temp folder, you can delete all the files.

Remove Cosd Virus via system restore

  • Press Windows Key + R buttons together on keyboard.
  • Type cmd in Run Box and then click OK button.
  • Type cd restore and press Enter, then type rstrui.exe and press Enter.
  • When System Restore window opens on your computer screen click Next button, then choose a System Restore point you have created in the past and click Next button.
  • Finally click on Yes button to start the system restoration process.

Remove Cosd via system restore

Note : This will only work if you have restore point set on your PC or it will give error message. Restoring the computer to a previous version may or may not remove .Cosd File Virus. Most of the times, virus just delete all the restore points. If this trick does not work for you then don’t get disappointed.

After restoring your computer, we recommend you to run a thorough scan of PC using a Powerful Anti-Malware program to detect and remove any hidden threats. In most cases, virus may spread through any files outside of C drive because system restoring only affect the C drive. There may be some Virus related file hiding your PC, and it never hurts to double-check.

Some times, system restore doesn’t work or virus can just remove the restore points. In such you will probably have no other choice than choosing the Automatic Removal Process. It is the best and error free method to find and remove threats from your computer. Additionally you should also check some important malware prevention tips provided here in this guide to avoid similar virus attacks in the future.

Remove Cosd From MacOS

If you are a mac user, and your machine got infected by this nasty file encrypting malware then you need to remove it as soon as possible. Although Mac system are quite safe but they still do get infected. So you can delete this infection using below steps:

Stop Malicious Program From Activity Monitor

  • First you need to open Utilities folder on your Mac system.
  • Find the Activity Monitor icon and double-click on it to open.
  • Find Cosd related process, click cross button from upper left side corner to end task.
  • A pop-up dialogue box will appear on screen, click on Force Quit button.

Remove Virus From Application Folder

  • First go to Dock option (bottom of your screen) then click on Finder App.
  • Now you have to open the Applications Folders to see all the programs.
  • Find Cosd or any other unwanted program then move it to Trash.

Remove Cosd From Mac

Attention : If you are not tech savvy, then it could be quite difficult to remove Cosd manually from your mac. The best way is to download ComboCleaner Mac Anti-Malware and see if it can detect all hidden threats and viruses on your computer. Its really super easy and you should give it a try.

ComboCleaner Mac Antivirus allows you to scan your mac for threats and viruses for free, but you will need to purchase full license to remove found threats. Read EULA.


Tips To Prevent .Cosd Virus in Future

  • Use a good anti-virus, be it a free version but don’t use cracked security programs.
  • Make sure that your Windows firewall is active, so it can block upcoming threats.
  • Keep your Windows/Mac OS and other programs updated to avoid vulnerabilities.
  • Download updates only from official websites, don’t use suspicious sites.
  • Never download and install pirated software, games or illegal patches on your PC.
  • Do not open spam mails from unknown sender and scan all attachments before opening.
  • Never download freeware third-party programs from unreliable sources or websites.
  • Avoid connecting your PC to unsafe public Wi-Fi to protect your privacy.
  • You can also use a VPN to spoof your connection and avoid malicious sites.
  • Create a system restore point on your system for security purpose.
  • Keep backup of all your important files to avoid data loss.

Report cyber attack to Authorities

If you are also a Victim of Cosd virus then you should report this cyber crime incident to legal authority in your county. Here are the lit of some of the official government websites for reporting fraud and scam activities:

You can also search to find the Internet Crime Authority in your counter. Meanwhile it will not help you remove or restore your files in any way but its merely an information to authorities. Once you register your complain, authorities might look into and take preventive measures to stop further attacks. However don’t get lured by third party criminal reporting sites or fake technical support websites. They are more like to cheat you instead of helping you.

tip Still having issues? Need help?

Some time threats like Cosd keep getting back on the machine, if all associated files are not removed. So you are advised to use a powerful Malware Removal Tool to run a thorough scan of your PC and delete all threats at once.

SpyHunter 5 Anti-Malware allows you, subject to a 48-hour waiting period, one remediation and removal for results found. Read SpyHunter 5 Review, EULA and Privacy Policy

About the author

Robert Calvert

Robert is the Chief Security Expert and Founder of PCSafetyGeek.com website. He is a cybersecurity enthusiast who loves to research about Malware outbreaks and write about their remedies. He also like to spend time trying new software, reviewing them and sharing IT news. However he is a real coffee lover and likes to play chess in spare time (which is quite rare 😜).

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