How to remove URSA ransomware

URSA ransomware is a data-locker that does not rename encrypted files

URSA ransomware is a type of computer virus that focuses on money extortion. Unlike many other threats of a similar kind, it does not append any extension to personal files, although it does use the encryption algorithm (RSA-2048)^[1] for the purpose. As a result, you will not be able to open any of the pictures, videos, documents, or other files without decryption software that is only be provided by hackers behind the malware.

There are two ransom notes that the URSA virus drops as soon as it finishes to lock files – RECOVER_YOUR_FILES.HTML and RECOVER_YOUR_FILES.TXT. In these files, attackers explain what happened to victims' data and ask them to download the Tor browser. This would provide access to a specially-crafted webpage with extensive instructions on how to buy Bitcoins and pay $350 for a decryptor.

There is a lot of ransomware around. While established strains are going steady with several variants being released weekly (for example, Djvu actors released Pola and Wbxd in one week alone), new ones are emerging as well. Ursa 1.0 is one of them, and it seems like these hackers are not playing games.

This virus has several features that we do not see that often overall – they include:

• It does not append any file extensions
• It does not provide contact email and relies on Tor instead
• Uses carefully crafted ransom notes.

While there are no extensions present, the files are still encrypted, and you will not be able to open them. As hackers explain within the ransom note, you need a private key that is only available to the attackers. Unfortunately, there are no 100% effective methods that would replace the keys provided by malware authors – the only secure way to restore data is by using backups that should have been created before the attack happened.

One of the first things you might see after the infection is the following ransom note:

All your files have been encrypted with URSA 1.0

* What happend to your files?
All of your files were protected by a strong encryption with RSA-2048 using Ursa 1.0
More information about the encryption keys using RSA-2048 can be found here: hxxps://en.wikipedia.org/wiki/RSA_(cryptosystem)

* What does this mean?
This means that the structure and data within your files have been irrevocably changed,
you will not be able to work with them, read them or see them, it is the same thing as losing them forever, but with our help, your can restore them.

* How did this happen?
Especially for you, on our server was generated the secret key pair RSA-2048 public and private.
All your files were encrypted with the public key, which has been transferred to your computer via the internet. Decrypting of your files is only possible with the help of the private key and decrypt program, which is on our secret server.

* What do i do?
Alas, if you do not take the necessary measures for the specified time then the conditions for obtaining the private key will be changed.
If you really value your data. then we suggest you go directly to your personal page. Do not waste valuable time searching for other solutions, because they do not exist.

Important information.

Your Personal Page: 

1. Download and install tor-browser hxxps://www.torproject.org/download
2. After a successful installation, run the browser and wait for initialization.
3. Type or copy your personal page that you see above, into the address bar.
4. Follow the instructions on your personal page.

As you can see, Ursa 1.0 virus authors do a good job at explaining to victims what to do next – it is in their best interest to do so in order to get the payment of 0.0086 BTC. On the specially crafted Tor page, the attackers also state that users only have one week to provide payment for the URSA decryptor; otherwise, the files will be lost forever.

Threatening with permanent data loss is a common tactic among ransomware authors and was especially popular previously. The time limit is there to intimidate victims and make them pay quicker. Despite this, there is no proof or guarantee that hackers will indeed provide the decryption tool after payment, and if they will delete the private key after a week.

Therefore, if you decide to pay, you risk not only your files but also your money, hence security experts^[2] advise against it. Instead, you can rely on alternative methods that might help you, although keep in mind that you need to remove Ursa ransomware before applying them. Also, making encrypted file backups on a separate medium (such as a USB flash drive) is recommended.

Ursa virus removal can be performed with a variety of security tools – such as SpyHunterCombo Cleaner. However, system repair should be done with special repair software. FortectIntego can fix the Windows registry, replace damaged system files with new ones and prevent crashes, errors, and other stability issues after the virus is eliminated.

Malicious actors use several methods for malware distribution

If you are wondering how you got infected with malware, it is likely to be due to actions that are considered risky. Typically, cybercriminals distribute malware in several ways in order to make the infection rate, along with payment possibilities, much higher. Here are a few methods that are worth mentioning:

• Repacked installers for various software, such as Adobe Reader
• Software cracks, loaders or keygens
• Malicious spam email attachments and hyperlinks
• Software vulnerabilities and drive-by downloads^[3]
• Fake updates, etc.

Therefore, in order to avoid the treacherous ransomware infection in the future, we highly recommend you practice caution when using a computer connected to the internet. While employing a robust security tool can prevent most of the infections, disabling it manually to download a software crack could still end up badly.

Stay away from email attachments that ask you to enable macro function, patch all the software on your computer, use strong passwords for all your accounts (and never reuse them!), and never disable your security software to install a pirated game or software crack.

Ursa 1.0 removal and file recovery options

As we already mentioned, there is no reliable way to restore the encrypted files without acquiring the decryption key from cybercriminals. Because it is also unique, you won't get away with contacting other victims and applying it to your files – this is one of the reasons why ransomware is so effective when it comes to extortion.

Paying criminals could be a waste of money, as they are not obligated to send you a decryptor (even if they might say so initially). Thus, rather focus on Ursa ransomware removal and alternative file recovery methods.

While you technically can remove Ursa virus manually, it requires superior computer skills. Thus, we advise you to stick to a more reliable method that would find and delete malware automatically – perform a full system scan with SpyHunterCombo Cleaner or MalwarebytesMalwarebytes security applications.

After elimination, you could use FortectIntego that would restore damaged system files and prevent crashes or errors due to the malware attack. Finally, you should try using alternative data recovery methods instead of paying the attackers – we provide them below.