KRONOS Ransomware - How to remove

This KRONOS isn’t the banking trojan — this is a file-encrypting virus that gives the “KRONOS” suffix to each of the encrypted files. It attacks Windows computers, renames and encrypts files (except for system files), and leaves behind a ransom note called HowToDecrypt.txt. It seems to be unrelated to the Kronos trojan or the WannaCry attack, but is dangerous in its own right.

KRONOS is a file-encrypting virus. Its creators spread it together with their email address and instructions on how to buy Bitcoins. That’s how most ransomware works nowadays. The extortionists hope that desperate victims will send them money in hopes of getting their files back.

Whether the people behind KRONOS can actually decrypt the locked files is an open question. Paying criminals ransom money is almost never a good idea, if only because they can’t be guaranteed to keep their end of the bargain and there’s no way to get back your files after failing to receive help.

The KRONOS ransomware is targeted at individual PC users, rather than small businesses. It’s meant to take away people’s most important data, like family photos, personal projects, job files, and push them to send money to the extortionists in false hopes that the data will be restored.

Secure browsing, real-time protection, and especially backups could help protect data against being lost. Even once your computer was infected, there are some options for recovering the files — not all hope is lost yet:

Details of the KRONOS ransomware	Extension of the encrypted files — Email=[[email protected]]ID=[…].KRONOS Ransom note file — HowToDecrypt.txt Email address — [email protected]
Distribution	Infected downloads Remote desktop protocol Malicious email spam Infected websites
Remove KRONOS	Remove malware automatically (SpyHunter)
Restore the files	From backups System restore Shadow volume copies Data recovery Wait for a free decrypter

 

HowToDecrypt.txt contents are the message from the creators of this ransomware:

Your Files Have Been Encrypted
If You Need Your Files You Should Pay Decryption Price
The Steps For Getting Decryption Tool :
1-Send Id On The Files Or  HowtoDecrypt.txt Files to Our Email
2-Send 1MB File For Getting Decryption Test to Make Sure You Can Get Your Files Back With Us(The Test File Should Not Contain Valuable Data Like Databases Excel Sheets or Backups)
3- Pay Decryption Price ( Payment Should Be With Bitcoin )
4- Get Decryption Tool With Key
Attention:
Using 3rd Party Applications or  Recovery Tools May Damage Your Files permanetly
Your ID :[random]
Our Email: [email protected]
You Can Learn How to Buy Bitcoin From This links Below
https://localbitcoins.com/buy_bitcoins
https://www.coindesk.com/information/how-can-i-buy-bitcoins

How ransomware spreads

All the ways that KRONOS spreads aren’t yet known, but we can speculate. The most common ways are email spam and remote desktop hacks, followed by infected programs being downloaded from the internet. KRONOS’ predecessors mostly spread in activators and cracks, though.

Ransomware being downloaded from the internet happens all the time and that’s also done by Djvu-type ransomware, totally unrelated to KRONOS. Malware is hidden in pirated files, cracks, activators, activated Office, Adobe, or other expensive programs. People sometimes even turn off their security software to not interfere with the pirating. This is dangerous — every file that was downloaded should be scanned before it’s run, the results should be taken into consideration. Otherwise, KRONOS would easily be able to lock your files — modern ransomware is very fast.

If KRONOS is spread by spam emails, you might have opened one that might have baffled you: it would likely have been a letter that carried a link or a file that needed to be opened. The email wouldn’t have been cryptic and lacking details, meant to invoke curiosity. The attached file would have included malicious code that would download and install KRONOS.

Attacks targeted at Remote desktop access are more sophisticated and they’re often used against big organizations and companies. A lot of people don’t even have RDP turned in it their computer. Nevertheless, if KRONOS appeared completely out of nowhere and no other explanation is found, it must have been RDP. Probably, the username and password were hacked, maybe you leaked them previously.

Importantly, keep a copy of your files saved somewhere separate from your computer, so that when KRONOS or another ransomware does attack you, you can recover those files easily. Otherwise, you risk losing your files not just to ransomware, but to mechanical failure and theft.

How to restore the files and get rid of KRONOS

Those who have backups of their data should restore from there (after deleting all malware, of course). That’s because, so far, there is no way to reverse KRONOS’s encryption of the files. It’s likely that there won’t be — earlier versions of KRONOS didn’t have encryption entirely figured out and used to just fill the files with zeroes, so you probably shouldn’t trust the extortionists to have done a good job.

For now the following section has info on how the previous versions of the files can be restored without relying on decryption.

You can use any competent anti-malware program (like SpyHunter) to get rid of KRONOS and make sure this ransomware doesn’t leave any surprises behind, like keyloggers or backdoors. You might have to scan using Safe Mode, or maybe after killing all malicious processes. Otherwise, serious malware could still evade detection.

Automatic Malware removal tools

How to recover KRONOS Ransomware encrypted files and remove the virus

Step 1. Restore system into last known good state using system restore

1. Reboot your computer to Safe Mode with Command Prompt:

for Windows 7 / Vista/ XP

• Start → Shutdown → Restart → OK.
• Press F8 key repeatedly until Advanced Boot Options window appears.
• Choose Safe Mode with Command Prompt.

for Windows 8 / 10

• Press Power at Windows login screen. Then press and hold Shift key and click Restart.
• Choose Troubleshoot → Advanced Options → Startup Settings and click Restart.
• When it loads, select Enable Safe Mode with Command Prompt from the list of Startup Settings.

 

2.Restore System files and settings.

• When Command Prompt mode loads, enter cd restore and press Enter.
• Then enter rstrui.exe and press Enter again.
• Click “Next” in the windows that appeared.
• Select one of the Restore Points that are available before KRONOS has infiltrated to your system and then click “Next”.
• To start System restore click “Yes”.

 

Step 2. Complete removal of KRONOS Ransomware

After restoring your system, it is recommended to scan your computer with an anti-malware program, like Spyhunter and remove all malicious files related to KRONOS. You can check other tools here.  

Step 3. Restore KRONOS Ransomware affected files using Shadow Volume Copies

If you do not use System Restore option on your operating system, there is a chance to use shadow copy snapshots. They store copies of your files that point of time when the system restore snapshot was created. Usually KRONOS tries to delete all possible Shadow Volume Copies, so this methods may not work on all computers. However, it may fail to do so. Shadow Volume Copies are only available with Windows XP Service Pack 2, Windows Vista, Windows 7, and Windows 8. There are two ways to retrieve your files via Shadow Volume Copy. You can do it using native Windows Previous Versions or via Shadow Explorer. a) Native Windows Previous Versions Right-click on an encrypted file and select Properties → Previous versions tab. Now you will see all available copies of that particular file and the time when it was stored in a Shadow Volume Copy. Choose the version of the file you want to retrieve and click Copy if you want to save it to some directory of your own, or Restore if you want to replace existing, encrypted file. If you want to see the content of file first, just click Open.

b) Shadow Explorer It is a program that can be found online for free. You can download either a full or a portable version of Shadow Explorer. Open the program. On the left top corner select the drive where the file you are looking for is a stored. You will see all folders on that drive. To retrieve a whole folder, right-click on it and select “Export”. Then choose where you want it to be stored.

Step 4. Use Data Recovery programs to recover KRONOS Ransomware encrypted files

There are several data recovery programs that might recover encrypted files as well. This does not work in all cases but you can try this:

• We suggest using another PC and connect the infected hard drive as slave. It is still possible to do this on infected PC though.
• Download a data recovery program.
• Install and scan for recently deleted files.

Note: In many cases it is impossible to restore data files affected by modern ransomware. Thus I recommend using decent cloud backup software as precaution. We recommend checking out Carbonite, BackBlaze, CrashPlan or Mozy Home.