How to remove Cronus Ransomware and decrypt your files

What is Cronus Ransomware

Cronus Ransomware is a new strain of malware that has been actively targeting users, particularly through phishing tactics aimed at PayPal customers since at least July 2024. The attack typically begins with a socially engineered document titled paypal_charges.doc, which entices victims to open it. Upon execution, this document connects to an external file hosting service to download what masquerades as a JPG file, but is actually a heavily obfuscated PowerShell script. Once executed, the ransomware encrypts files on the victim’s system and appends random file extensions to those encrypted files, complicating recovery efforts. Known extensions added by the Cronus Ransomware include variations resembling random characters, making it difficult for users to recognize the modified files. Following the encryption process, victims receive a ransom note named cronus.txt, which outlines the demands for payment to decrypt their files. The note typically contains instructions on how to proceed with the payment, often demanding cryptocurrency as the preferred method.

As of now, there are no known decryption tools specifically designed to counteract Cronus Ransomware, leaving many victims in the lurch when their files become inaccessible. Without a reliable decryption option, the only practical solutions remain to either restore files from backups or pay the ransom, both of which carry significant risks. Users are urged to regularly back up important data to an isolated storage solution, thereby minimizing potential losses in the event of such attacks. In attempts to recover encrypted files independently, victims have a slim chance by using file recovery software, but this is not guaranteed. It is crucial to approach ransom situations with caution since paying does not assure that files will be decrypted or that systems won’t be reinfected. Furthermore, individuals are encouraged to enhance their defense mechanisms through robust cybersecurity practices, such as multi-factor authentication and being vigilant about suspicious emails and attachments.

How Cronus Ransomware infects computers

Cronus Ransomware primarily targets users through deceptive phishing campaigns, often disguised as legitimate communications from well-known services such as PayPal. Its infection process begins with the delivery of a malicious document, typically named something innocuous like “paypal_charges.doc.” When unsuspecting users open this document, it triggers the download of a seemingly harmless JPG file from a file hosting service. However, this file is actually a heavily obfuscated PowerShell script that executes once downloaded. The script then initiates the encryption of files on the infected machine, appending random extensions to the affected files, thereby rendering them inaccessible to the user. This sophisticated method of social engineering, combined with the use of obfuscation techniques, makes Cronus Ransomware particularly insidious, posing a significant threat to both individual and organizational cybersecurity.

1. Download Cronus Ransomware Removal Tool
2. Get decryption tool for encrypted files
3. Recover encrypted files with Stellar Data Recovery Professional
4. Restore encrypted files with Windows Previous Versions
5. Restore files with Shadow Explorer
6. How to protect from threats like Cronus Ransomware

Cronus Ransomware files:


cronus.txt
{randomname}.exe


Cronus Ransomware registry keys:

no information

How to decrypt and restore encrypted files

Use automated decryptors

Download Kaspersky RakhniDecryptor

Use following tool from Kaspersky called Rakhni Decryptor, that can decrypt encrypted files. Download it here:

Download RakhniDecryptor

There is no purpose to pay the ransom because there is no guarantee you will receive the key, but you will put your bank credentials at risk.

Dr.Web Rescue Pack

Famous antivirus vendor Dr. Web provides free decryption service for the owners of its products: Dr.Web Security Space or Dr.Web Enterprise Security Suite. Other users can ask for help in the decryption of encrypted files by uploading samples to Dr. Web Ransomware Decryption Service. Analyzing files will be performed free of charge and if files are decryptable, all you need to do is purchase a 2-year license of Dr.Web Security Space worth $120 or less. Otherwise, you don’t have to pay.

If you are infected with Cronus Ransomware and removed from your computer you can try to decrypt your files. Antivirus vendors and individuals create free decryptors for some crypto-lockers. To attempt to decrypt them manually you can do the following:

Use Stellar Data Recovery Professional to restore encrypted files

1. Download Stellar Data Recovery Professional.
2. Click Recover Data button.
3. Select type of files you want to restore and click Next button.
4. Choose location where you would like to restore files from and click Scan button.
5. Preview found files, choose ones you will restore and click Recover.

Download Stellar Data Recovery Professional

Using Windows Previous Versions option:

1. Right-click on infected file and choose Properties.
2. Select Previous Versions tab.
3. Choose particular version of the file and click Copy.
4. To restore the selected file and replace the existing one, click on the Restore button.
5. In case there are no items in the list choose an alternative method.

Using Shadow Explorer:

1. Download Shadow Explorer program.
2. Run it, and you will see screen listing of all the drives and the dates that shadow copy was created.
3. Select the drive and date that you want to restore from.
4. Right-click on a folder name and select Export.
5. In case there are no other dates in the list, choose an alternative method.

If you are using Dropbox:

1. Login to the Dropbox website and go to the folder that contains encrypted files.
2. Right-click on the encrypted file and select Previous Versions.
3. Select the version of the file you wish to restore and click on the Restore button.

How to protect computer from viruses, like Cronus Ransomware, in future

1. Get special anti-ransomware software

Use ZoneAlarm Anti-Ransomware

Famous antivirus brand ZoneAlarm by Check Point released a comprehensive tool, that will help you with active anti-ransomware protection, as an additional shield to your current protection. The tool provides Zero-Day protection against ransomware and allows you to recover files. ZoneAlarm Anti-Ransomware is compatible with all other antiviruses, firewalls, and security software except ZoneAlarm Extreme (already shipped with ZoneAlarm Anti-Ransomware) or Check Point Endpoint products. The killer features of this application are: automatic file recovery, overwrite protection that instantly and automatically recovers any encrypted files, file protection that detects and blocks even unknown encryptors.

Download ZoneAlarm Anti-Ransomware

2. Back up your files

As an additional way to save your files, we recommend online backup. Local storage, such as hard drives, SSDs, flash drives, or remote network storage can be instantly infected by the virus once plugged in or connected to. Cronus Ransomware uses some techniques to exploit this. One of the best services and programs for easy automatic online backup is iDrive. It has the most profitable terms and a simple interface. You can read more about iDrive cloud backup and storage here.

3. Do not open spam e-mails and protect your mailbox

Malicious attachments to spam or phishing e-mails are the most popular method of ransomware distribution. Using spam filters and creating anti-spam rules is good practice. One of the world leaders in anti-spam protection is MailWasher Pro. It works with various desktop applications and provides a very high level of anti-spam protection.

Download MailWasher Pro