RSAUtil Virus – Remove and Restore Files

RSAUtil Virus – Remove and Restore Files

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This article will aid you in removing the RSAUtil ransomware fully. Follow the ransomware removal instructions given at the end of the article.

The RSAUtil ransomware has been discovered by the malware researcher known by the handle @PolarToffee on Twitter. It will encrypt your files, while adding the extension to them afterward. When a computer system gets infected, the RSAUtil virus will show a ransom note and a window with instructions about paying the ransom.

Threat Summary

TypeRansomware, Cryptovirus
Short DescriptionThe ransomware virus will encrypt your files and show a message screen with ransomware instructions for payment, including a ransom note.
SymptomsThe ransomware will encrypt your files while placing the extension to them, where the ID is specific for each user.
Distribution MethodSpam Emails, Email Attachments
Detection Tool See If Your System Has Been Affected by RSAUtil


Malware Removal Tool

User ExperienceJoin Our Forum to Discuss RSAUtil.
Data Recovery ToolWindows 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.

RSAUtil Virus – Update May 2018

The month of May brings a new update to the RSAUtil Virus. Malware analysts have seen samples with a modified ransom note and new contact e-mail addresses. The ransom note is inside a file called “How_return_files.txt” and can be viewed from the below screenshot:

The ransom note states the following:

Hi friend… :)
For instructions on how to recovery the files, write to me:
In the letter, indicate your personal ID (see the file format).
If you have not received an answer, write to me again.

The following e-mail addresses are used as a way of contacting the cybercriminals:


During the past few months more samples have been found, which had minor changes to the malware. The article will get updated if something new surrounding the malware threat is discovered.

RSAUtil Virus – Update December 2017

Malware researchers have discovered changes made to the RSAUtil Virus, this December, with a new ransom note and new extensions. The ransom note is inside a file called “How_return_files.txt” and can be viewed down here:

That ransom note states the following:

To get an intuition for decrypting all the files, write here:

In the letter, indicate your personal ID (see the file format).
If you have not received an answer, write to me again. Do not try to restore files yourself, this
can lead to the loss of your files!!!


As to the new extensions that encrypted files receive – they are “.ID.VENDETTA” and “.ID.GORILLA“. For the VENDETTA extension, the emails are changed inside the note to the following ones:


It seems that there can be more changes as well, but for the time being this is the pattern that the ransomware’s developers use for changing their malware. If there are more news regarding the matter, the article will get duly updated.

RSAUtil Virus – Infection Spread

RSAUtil ransomware could spread its infection in different ways. The payload file which initiates the malicious script for this ransomware, that in turn infects your computer machine, has been seen around the Internet. Samples of this ransomware have been found by a few different malware researchers. You can see the detections of security vendors for one of those samples which is called “RSAUtil.exe” by checking the screenshot of the VirusTotal platform below:

The RSAUtil ransomware could also spread its payload file on social media websites and file-sharing networks. Freeware applications which are found on the Web could be presented as useful but at the same time could be hiding the malicious script for this cryptovirus. Don’t be opening files right when you have downloaded them, especially if they come from sources such as suspicious links or emails. Instead, you should scan them beforehand with a security tool, while also checking the sizes and signatures of those files for anything that seems unusual. You should read the ransomware prevention tips located on our forum.

RSAUtil Virus – Technical Overview

RSAUtil is how a new cryptovirus is dubbed, which is written on the Delphi programming language. The main reason for that name may be that one of its malware samples bears the same name and that it probably uses an “RSA Utility” for encryption. After your files get encrypted, they will all receive the extension. One of the first samples of the virus was discovered by the malware researcher known as @PolarToffee on Twitter.

The RSAUtil ransomware could make entries in the Windows Registry aiming to achieve a higher level of persistence. Those registry entries are typically designed in a way that will start the virus automatically with each launch of the Windows Operating System. An example of such an entry is the following:


When the encryption process is finished a ransom message will display within a window and another smaller note as a picture. The window is with a black background and provides instructions on what steps to make to pay the ransom. You can see that message in the screenshot provided below:

The ransom message loads in a window and reads the following:

Your ID 83624883
Your documents, photos, database, save games and other important data was encrypted.
Data recovery the necessary interpreter. To get the interpreter, should send an email to or
In a letter to include Your personal ID (see the beginning of this document).
In response to the letter You will receive the address of your Bitcoin wallet to which you want to perform the transfer.
When money transfer is confirmed, You will receive the decrypter file for Your computer.
After starting the programm-interpreter, all Your files will be restored.
Attention! Do not attempt to remove a program or run the anti-virus tools.

Another message accompanies the ransom message window, and that is a small note:

That note reads:

Hello my friend!
All files on your PC encryphted!
my email: or

As clearly seen from the ransom message above and also written in a file called “How_return_files.txt” (wich is dropped inside every folder with encrypted files), the developer of the RSAUtil virus wants you to send a message to one of the following two email addresses:


However, if you get your personal computer infected with the malware, you should NOT under any circumstances pay anything to the cybercriminal behind it. Nobody can give you a guarantee that you will get your files decrypted upon paying.

RSAUtil Virus – Encryption Process

RSAUtil ransomware will most probably search and encrypt files, which have the following extensions:

→.doc, .docx, .pdf, .db, .jpg, .png, .ppt, .pptx, .txt, .xls, .xlsx

The extensions mentioned above are for the most commonly used file types under the Windows Operating System, but that list is most probably bigger and could get updated. The RSA algorithm is believed to be applied here in the encryption process. The extension is put to all encrypted files, where the ID number is scpecific for each user. Here the ID is 83624883, so the full extension appended to an encrypted file is

In case the ransomware runs on a Virtual Machine, it won’t encrypt files, but only display the following error message:

The RSAUtil cryptovirus could be set to erase the Shadow Volume Copies from the Windows Operating System by initiating the following command:

→vssadmin.exe delete shadows /all /Quiet

The execution of that command will make the encryption process more viable, since it eliminates one of the prominent ways for the restoration of your files.

Remove RSAUtil Virus and Restore Files

If your computer got infected with the RSAUtil 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.


Berta Bilbao

Berta is a dedicated malware researcher, dreaming for a more secure cyber space. Her fascination with IT security began a few years ago when a malware locked her out of her own computer.

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