The .c0hen virus is a ransomware that is currently set against target end users on a global scale. There is no information available about the hacking group behind it. It is believed to be a new iteration of the famous ransomware family. This is one of the reasons why we believe that the hackers are experienced.
Once the .c0hen virus has started it will execute its built-in sequence of dangerous commands. Depending on local conditions or the specific hacker instructions various actions will take place. The file encryption will begin after them — the encrypting component will use a built-in list of target file type extensions. In the end the victim files will be renamed with the .c0hen extension.
Threat Summary
| Name | C0hen virus |
| Type | Ransomware, Cryptovirus |
| Short Description | The ransomware encrypts files on your computer machine and demands a ransom to be paid to allegedly restore them. |
| Symptoms | The ransomware will blackmail the victims to pay them a decryption fee. Sensitive user data may be encrypted by the ransomware code. |
| Distribution Method | Spam Emails, Email Attachments |
| Detection Tool |
See If Your System Has Been Affected by malware
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Malware Removal Tool
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User Experience | Join Our Forum to Discuss C0hen virus. |
| Data Recovery Tool | Windows Data Recovery by Stellar Phoenix Notice! This product scans your drive sectors to recover lost files and it may not recover 100% of the encrypted files, but only few of them, depending on the situation and whether or not you have reformatted your drive. |
.c0hen Virus – Spread and Impact
The .c0hen virus is a new ransomware malware which was reported to the security community recently. The acquired sample is an executable file giving us information that it is probably currently being tested or in a development phase. Usually the ransomware code is hidden or delivered through some kind of a script. Both experienced and beginner hackers can be behind any potential attacks. Most commonly they will use the common methods of sending out such threats — most notably this will include different kinds of social engineering tactics that will impersonate companies or web services. This is done by sending out such emails or hosting fake web pages. Both of them will imitate the company or service by implementing their own layout, style and text contents. Alternatively the criminals will inflict the infection by creating different file carriers which can be practically anything that the users may find appealing. Common tactics include the delivery of malware documents that contain virus-installing macros or .c0hen virus infected setup bundles.
Even though the .c0hen virus doesn’t appear to be live in direct attacks the analyzed code reveals tt it does include a rich array of features. One of the distinct ones is the security overcome component — operating system settings and potentially anti-virus programs will be disabled. This is done so that the .c0hen virus will launch without any issues. This particular ransomware has also been confirmed to have some Trojan-like by deleting user and system data. There is an mechanism inside the code that would allow the criminals to monitor the behavior of the users, steal their files and even manipulate fields and interact with programs.
The .c0hen virus can become a persistent infection by manipulating system settings and configuration scripts. This ensures that the ransomware will start every time when the computer is booted. Advanced versions of this threat can disable access to the recovery boot options.
And even though the .c0hen virus will launch a ransomware engine at the moment the security cipher implemented in it is very weak. The captured samples shows that predefined file types will be encrypted and made inaccessible. The respective .c0hen virus extension will be applied to them.
Instead of a ransom note a lockscreen instance will be displayed asking a ransom fee payment.
NOTE: The testing versions have been found to have weak security and as such users can unlock their files by placing the following unlock key:
12309482354ab2308597u235fnq30045f
Remove .c0hen Virus
If your computer system got infected with the .c0hen Files ransomware virus, you should have a bit of experience in removing malware. You should get rid of this ransomware as quickly as possible before it can have the chance to spread further and infect other computers. You should remove the ransomware and follow the step-by-step instructions guide provided below.
Martin Beltov
Martin graduated with a degree in Publishing from Sofia University. As a cyber security enthusiast he enjoys writing about the latest threats and mechanisms of intrusion.
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Attention! SensorsTechForum strongly recommends that all malware victims should look for assistance only by reputable sources. Many guides out there claim to offer free recovery and decryption for files encrypted by ransomware viruses. Be advised that some of them may only be after your money.
As a site that has been dedicated to providing free removal instructions for ransomware and malware since 2014, SensorsTechForum’s recommendation is to only pay attention to trustworthy sources.
How to recognize trustworthy sources:
- Always check "About Us" web page.
- Profile of the content creator.
- Make sure that real people are behind the site and not fake names and profiles.
- Verify Facebook, LinkedIn and Twitter personal profiles.
About the C0hen virus Research
The content we publish on SensorsTechForum.com, this C0hen virus how-to removal guide included, is the outcome of extensive research, hard work and our team’s devotion to help you remove the specific malware and restore your encrypted files.
How did we conduct the research on this ransomware?
Our research is based on an independent investigation. We are in contact with independent security researchers, and as such, we receive daily updates on the latest malware and ransomware definitions.
Furthermore, the research behind the C0hen virus ransomware threat is backed with VirusTotal and the NoMoreRansom project.
To better understand the ransomware threat, please refer to the following articles which provide knowledgeable details.
References
1. How to Recognize Spam Emails with Ransomware
2. How Does Ransomware Encryption Work?
3. How to Decrypt Ransomware Files
4. Ransomware Getting Greedier and Bigger, Attacks Increase by 40%
5. 1 in 5 Americans Victim of Ransomware
How to Remove C0hen virus from Windows.
Step 1: Boot Your PC In Safe Mode to isolate and remove C0hen virus
1. Hold Windows Key + R.
2. The "Run" Window will appear. In it, type "msconfig" and click OK.
3. Go to the "Boot" tab. There select "Safe Boot" and then click "Apply" and "OK".
4. When prompted, click on "Restart" to go into Safe Mode.
5. You can recognise Safe Mode by the words written on the corners of your screen.
Step 2: Uninstall C0hen virus and related software from Windows
Here is a method in few easy steps that should be able to uninstall most programs. No matter if you are using Windows 10, 8, 7, Vista or XP, those steps will get the job done. Dragging the program or its folder to the recycle bin can be a very bad decision. If you do that, bits and pieces of the program are left behind, and that can lead to unstable work of your PC, errors with the file type associations and other unpleasant activities. The proper way to get a program off your computer is to Uninstall it. To do that:
1. Hold the Windows Logo Button and "R" on your keyboard. A Pop-up window will appear.
2. In the field type in "appwiz.cpl" and press ENTER.
3. This will open a window with all the programs installed on the PC. Select the program that you want to remove, and press "Uninstall"
Follow the instructions above and you will successfully uninstall most programs.
Step 3: Clean any registries, created by C0hen virus on your computer.
The usually targeted registries of Windows machines are the following:
- HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
You can access them by opening the Windows registry editor and deleting any values, created by C0hen virus there. This can happen by following the steps underneath:
1. Open the Run Window again, type "regedit" and click OK.
2. When you open it, you can freely navigate to the Run and RunOnce keys, whose locations are shown above.
3. You can remove the value of the virus by right-clicking on it and removing it.
Tip: To find a virus-created value, you can right-click on it and click "Modify" to see which file it is set to run. If this is the virus file location, remove the value.
Before starting "Step 4", please boot back into Normal mode, in case you are currently in Safe Mode.
This will enable you to install and use SpyHunter 5 successfully.
Step 4: Scan for C0hen virus with SpyHunter Anti-Malware Tool
1. Click on the "Download" button to proceed to SpyHunter's download page.
2. After you have installed SpyHunter, wait for it to update automatically.
3. After the update process has finished, click on the 'Malware/PC Scan' tab. A new window will appear. Click on 'Start Scan'.
4. After SpyHunter has finished scanning your PC for any files of the associated threat and found them, you can try to get them removed automatically and permanently by clicking on the 'Next' button.
Video Guide for Automatic and Fast Removal
Step 5 (Optional): Try to Restore Files Encrypted by C0hen virus.
Ransomware infections and C0hen virus aim to encrypt your files using an encryption algorithm which may be very difficult to decrypt. This is why we have suggested a data recovery method that may help you go around direct decryption and try to restore your files. Bear in mind that this method may not be 100% effective but may also help you a little or a lot in different situations.
1. Download the recommended Data Recovery software by clicking on the link underneath:
Simply click on the link and on the website menus on the top, choose Data Recovery - Data Recovery Wizard for Windows or Mac (depending on your OS), and then download and run the tool.
Step 6: How to Restore Files Encrypted by Ransomware (Video Guide)
Get rid of C0hen virus from Mac OS X.
Step 1: Uninstall C0hen virus and remove related files and objects
1. Hit the ⇧+⌘+U keys to open Utilities. Another way is to click on “Go” and then click “Utilities”, like the image below shows:
2. Find Activity Monitor and double-click it:
3. In the Activity Monitor look for any suspicious processes, belonging or related to C0hen virus:
4. Click on the "Go" button again, but this time select Applications. Another way is with the ⇧+⌘+A buttons.
5. In the Applications menu, look for any suspicious app or an app with a name, similar or identical to C0hen virus. If you find it, right-click on the app and select “Move to Trash
”.
6. Select Accounts, after which click on the Login Items preference.
Your Mac will then show you a list of items that start automatically when you log in. Look for any suspicious apps identical or similar to C0hen virus. Check the app you want to stop from running automatically and then select on the Minus (“-“) icon to hide it.
7. Remove any left-over files that might be related to this threat manually by following the sub-steps below:
- Go to Finder.
- In the search bar type the name of the app that you want to remove.
- Above the search bar change the two drop down menus to “System Files” and “Are Included” so that you can see all of the files associated with the application you want to remove. Bear in mind that some of the files may not be related to the app so be very careful which files you delete.
- If all of the files are related, hold the ⌘+A buttons to select them and then drive them to “Trash”.
In case you cannot remove C0hen virus via Step 1 above:
In case you cannot find the virus files and objects in your Applications or other places we have shown above, you can manually look for them in the Libraries of your Mac. But before doing this, please read the disclaimer below:
1: Click on "Go" and Then "Go to Folder" as shown underneath:
2: Type in "/Library/LauchAgents/" and click Ok:
3: Delete all of the virus files that have similar or the same name as C0hen virus. If you believe there is no such file, do not delete anything.
You can repeat the same procedure with the following other Library directories:
→ ~/Library/LaunchAgents
/Library/LaunchDaemons
Tip: ~ is there on purpose, because it leads to more LaunchAgents.
Step 3 (Optional): Try to Restore Files Encrypted by C0hen virus.
Ransomware infections and C0hen virus aim to encrypt your files using an encryption algorithm which may be very difficult to decrypt. This is why we have suggested a data recovery method that may help you go around direct decryption and try to restore your files. Bear in mind that this method may not be 100% effective but may also help you a little or a lot in different situations.
1. Download the recommended Data Recovery software by clicking on the link underneath:
Simply click on the link and on the website menus on top, choose Data Recovery - Data Recovery Wizard for Windows or Mac (depending on your OS), and then download and run the tool.
C0hen virus FAQ
What is C0hen virus ransomware and how does it work?
C0hen virus is a ransomware infection - the malicious software that enters your computer silently and blocks either access to the computer itself or encrypt your files.
Many ransomware viruses use sophisticated encryption algorithm how to make your files inaccessible. The goal of ransomware infections is to demand that you pay a ransom payment to get access to your files back.
How does C0hen virus ransomware infect my computer?
Via several ways.C0hen virus Ransomware infects computers by being sent via phishing e-mails, containing virus attachment.
This attachment is usually masked as an important document, like an invoice, bank document or even a plane ticket and it looks very convincing to users.
After you download and execute this attachment, a drive-by download occurs and your computer is infected with the ransomware virus.
Another way, you may become a victim of C0hen virus is if you download a fake installer, crack or patch from a low reputation website or if you click on a virus link. Many users report getting a ransomware infection by downloading torrents.
How to open .C0hen virus files?
You can't. At this point the .C0hen virus files are encrypted. You can only open them once they are decrypted.
Decryptor did not decrypt my data. What now?
Do not panic and backup the files. If a decryptor did not decrypt your .C0hen virus files successfully, then do not despair, because this virus is still new.
One way to restore files, encrypted by C0hen virus ransomware is to use a decryptor for it. But since it's a new virus, advised that the decryption keys for it may not be out yet and available to the public. We will update this article and keep you posted as soon as this decryptor is released.
How Do I restore ".C0hen virus" files (Other Methods)?
Yes, sometimes files can be restored. We have suggested several file recovery methods that could work if you want to restore .C0hen virus files.
These methods are in no way 100% guarantee that you will be able to get your files back. But if you have a backup, your chances of success are much greater.
How do I get rid of C0hen virus ransomware virus?
The safest way and the most efficient one for the removal of this ransomware infection is the use a professional anti malware software. It will scan for and locate C0hen virus ransomware and then remove it without causing any additional harm to your important .C0hen virus files.
Also, keep in mind that viruses like C0hen virus ransomware also install Trojans and keyloggers that can steal your passwords and accounts. Scanning your computer with an anti-malware software will make sure that all of these virus components are removed and your computer is protected in the future.
What to Do If nothing works?
There is still a lot you can do. If none of the above methods seem to work for you, then try these methods:
- Try to find a safe computer from where you can can login on your own line accounts like One Drive, iDrive, Google Drive and so on.
- Try to contact your friends, relatives and other people so that they can check if they have some of your important photos or documents just in case you sent them.
- Also, check if some of the files that were encrypted it can be re-downloaded from the web.
- Another clever way to get back some of your files is to find another old computer, a flash drive or even a CD or a DVD where you may have saved your older documents. You might be surprised what will turn up.
- You can also go to your email account to check if you can send any attachments to other people. Usually what is sent the email is saved on your account and you can re-download it. But most importantly, make sure that this is done from a safe computer and make sure to remove the virus first.
More tips you can find on our forums, where you can also asks any questions about your ransomware problem.
How to Report Ransomware to Authorities?
In case your computer got infected with a ransomware infection, you can report it to the local Police departments. It can help authorities worldwide track and determine the perpetrators behind the virus that has infected your computer. Below, we have prepared a list with government websites, where you can file a report in case you are a victim of a cybercrime:
Cyber-security authorities, responsible for handling ransomware attack reports in different regions all over the world:
- Germany - Offizielles Portal der deutschen Polizei
- United States - IC3 Internet Crime Complaint Centre
- United Kingdom - Action Fraud Police
- France - Ministère de l'Intérieur
- Italy - Polizia Di Stato
- Spain - Policía Nacional
- Netherlands - Politie
- Poland - Policja
- Portugal - Polícia Judiciária
- Greece - Cyber Crime Unit (Hellenic Police)
- India - Mumbai Police - CyberCrime Investigation Cell
- Australia - Australian High Tech Crime Center
Reports may be responded to in different timeframes, depending on your local authorities.
