How to remove Koom ransomware

Koom ransomware encourages people to pay up via _readme.txt file with a ransom demand

The malicious infection happens silently, but the fact that the Koom ransomware virus can run on the machine before it affects files makes it more persistent. The threat locks data and asks for money, promising to provide the decryption tool after the money transfer. However, that is not a truthful statement because, in most cases, ransomware developers do not provide any help and only focus on their profit.

Koom virus is a ransomware virus that renames files and appends the .koom extension onto each encrypted file's filename. The virus notifies victims by displaying the ransom note file named _readme.txt. The file includes a message from criminals, contact information, information on ransom payments.

The virus is a new, malicious ransomware program that has just been discovered. But it belongs to the ransomware family Djvu that has been known for a while and is actively releasing new versions every week with slightly altered features. One of its main functions appears to be preventing victims from accessing their files by encrypting them and appending the unique extension onto each encrypted file name. When it infects your computer, it will change those file names and alters various other settings to ensure the persistence of the threat.

The ransom note provides contact and payment information. It instructs victims to contact the attacker via manager@mailtemp.ch or managerhelper@airmail.cc email address within 72 hours from attack for a decryption tool that costs between $490-$980 depending on how soon they want it done. Additionally, cybercriminals inform their unfortunate captives that it is possible to send an encrypted file for free decryption, but that alone might be dangerous.

ATTENTION!

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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:
manager@mailtemp.ch

Reserve e-mail address to contact us:
managerhelper@airmail.cc

Your personal ID:

We do not recommend contacting criminals at any cost. Experts^[2] always note that threat actors behind malware likeKoom ransomware can do things to fake legitimacy and trust between victims and extortionists, so the person whose files are captive would pay more willingly. That is never a good idea.

Possible .Koom file decryption

There are some versions of cryptocurrency-extortion threats that send the malicious files, other infections after the payment transfer for the promised decryption tool. However, the decryption process is not an easy thing. Official decryption tools take time to develop. The already existing decryptor from Emsisoft is partially helpful in such cases, but the success depends on the offline vs. online ID formation factor.

If you have infected your computer with one of the Djvu variants, you should try using Emsisoft decryptor for Djvu/STOP. It is important to mention that this tool will not work for everyone – it only works if data is locked with an offline ID due to malware failing to communicate with its remote servers.

Even if your case meets this condition, somebody from the victims has to pay criminals, retrieve an offline key, and then share it with security researchers at Emsisoft. As a result, you might not be able to restore the encrypted files immediately. Thus, if the decryptor says your data was locked with an offline ID but cannot be recovered currently, you should try later. You also need to upload a set of files – one encrypted and a healthy one to the company's servers before you proceed.

• Download the app from the official Emsisoft website.
• After pressing Download button, a small pop-up at the bottom, titled decrypt_STOPDjvu.exe should show up – click it.
• If User Account Control (UAC) message shows up, press Yes.
• Agree to License Terms by pressing Yes.
  
  
• After Disclaimer shows up, press OK.
• The tool should automatically populate the affected folders, although you can also do it by pressing Add folder at the bottom.
  
• Press Decrypt.
  
  

From here, there are three available outcomes:

1. “Decrypted!” will be shown under files that were decrypted successfully – they are now usable again.
2. “Error: Unable to decrypt file with ID:” means that the keys for this version of the virus have not yet been retrieved, so you should try later.
3. “This ID appears to be an online ID, decryption is impossible” – you are unable to decrypt files with this tool.

The important step – virus removal

The STOP/Djvu decrypter will stop the ransomware from running so that it can't continue encrypting your files, however, it doesn't completely remove the malware. This is not the same the other way around – anti-malware tools do not recover your files. Most anti-virus software detects malware and its pieces on the machine if you run a scan. You can rely on SpyHunterCombo Cleaner or MalwarebytesMalwarebytes and check the system thoroughly for all the virus files that need to get terminated.

Note that formatting hard drives and reinstalling with windows again is an option also but not really necessary as there are other apps available too. This threat's damage to the machine consists of affecting the registry, other files, and system directories. Those changes can damage functions further and cause issues with the machine beside the file locking. Eliminate the risk of getting your system damaged, and files encoded again by removing the virus completely.

The thing that concerns people is Koom virus encryption^[3] that causes file locking and issues with data recovery. It is common for users to panic and search for any possible file repair option, but anyone can claim to have the needed solution to get your money. The virus removal is more important than the file repair because you need to terminate the infection in the first place before you add any file copies on the machine or use recovery software. 

Once a computer is infected with malware, its system is changed to operate differently. For example, an infection can alter the Windows registry database, damage vital bootup, and other sections, delete or corrupt DLL files, etc. Once a system file is damaged by malware, antivirus software is not capable of doing anything about it, leaving it just the way it is. Consequently, users might experience performance, stability, and usability issues, to the point where a full Windows reinstallation is required.

Therefore, we highly recommend using a one-of-a-kind, patented technology of FortectIntego repair. Not only can it fix virus damage after the infection, but it can also remove malware that has already broken into the system thanks to several engines used by the program. Besides, the application can also fix various Windows-related issues that are not caused by malware infections, for example, Blue Screen errors, freezes, registry errors, damaged DLLs, etc.

• Download the application by clicking on the link above
• Click on the ReimageRepair.exe
  
• If User Account Control (UAC) shows up, select Yes
• Press Install and wait till the program finishes the installation process
• The analysis of your machine will begin immediately
• Once complete, check the results – they will be listed in the Summary
• You can now click on each of the issues and fix them manually
• If you see many problems that you find difficult to fix, we recommend you purchase the license and fix them automatically.

.koom file recovery

When the ransomware cannot connect to its command and control servers while encrypting your files, it uses a built-in encryption key that matches with all victims of the same variant. This means that every time there is a new variant/extension of the family, the threat goes for an offline ID. With this particular family, of theKoom virus affects machines and uses offline method, everyone who has their data encrypted by the same version will also have access to the decryption. It is possible to use just one specific private key, which could be helpful in situations.

However, the particular versions released after August 2019 mainly use online IDs, and the existing decryption tool is not helpful. The ransomware's ability to connect with command and control servers is a crucial element in its operation of encoding. When it encrypts files, the server responds by generating random keys for each infected computer – meaning that if you want your data back, there are no master keys available anywhere online or on-disk, which would unlock all locks at once.

With older variants, this was manageable as long as they had some help, but newer versions have become increasingly resilient against such efforts. Developers altered their encryption methods and these techniques to ensure persistence and keep the family of Djvu more dangerous. Unfortunately, that leavesKoom ransomware virus victims with fewer options for proper file recovery.

Since the official decryption tools take time to be made, you only can save some of the files alongside malicious pieces and wait for the development, or actions from law enforcement agencies. The family is well-known and dangerous enough to remain undetected. Criminals run their malicious programs for a long time, so rely on alternative options instead.

Unfortunately, many users do not prepare proper data backups prior to being attacked by ransomware, they might often lose access to their files permanently. Paying criminals is also very risky, as they might not fulfill the promises and never send back the required decryption tool.

While this might sound terrible, not all is lost – data recovery software might be able to help you in some situations (it highly depends on the encryption algorithm used, whether ransomware managed to complete the programmed tasks, etc.). Since there are thousands of different ransomware strains, it is immediately impossible to tell whether third-party software will work for you.

Install data recovery software

1. Download Data Recovery Pro.
2. Double-click the installer to launch it.
3. Follow on-screen instructions to install the software.
4. As soon as you press Finish, you can use the app.
5. Select Everything or pick individual folders. 
6. Press Next.
7. At the bottom, enable Deep scan and pick which Disks you want to be scanned.
8. Press Scan and wait till it is complete.
9. You can now pick which folders/files to recover – don't forget you also have the option to search by the file name!
10. Press Recover to retrieve your files.

The system can be damaged significantly, and all the Koom ransomware virus activities might cause more damage than the encryption of files. You can remove the threat with tools like SpyHunterCombo Cleaner or MalwarebytesMalwarebytes since those AV detection tools are the best for malware termination. However, you also need to think about problems with the system performance and data affected there, so run FortectIntego for the proper system repair procedures. You can also rely on additional helpful guides below.