Sigrun ransomware (Virus Removal Guide) - 2018 update

Sigrun virus Removal Guide

What is Sigrun ransomware?

Sigrun is a file-locking ransomware that demands ransom in Dash or Bitcoin for file decryption

Sigrun ransomware

Sigrun is a ransomware virus that was discovered by security researchers in the middle of May 2018.[1] Malware enters machine unnoticed, executes its payload and then locks up all audio, video, picture, text, database and other personal files. It uses complicated cryptography to add a .sigrun file extension, making all data unusable. The virus drops ransom note into each of the “RESTORE-SIGRUN.txt” into each of the infected folders and also opens up a browser tab with the same message in .html format. Users are asked to contact hackers via in order to get their files back. Victims are asked to pay up to $2,500 in Dash or Bitcoin cryptocurrency, although Russians can get a decryptor for free.

Name Sigrun
Type Ransomware
File extension .sigrun
Ransom notes RESTORE-SIGRUN.txt and RESTORE-SIGRUN.html
Contact email
Distribution Spam emails, fake downloads, repacked software installers, etc.
Symtoms Unusable files
Elimination Use reputable security software ReimageIntego, SpyHunter 5Combo Cleaner or Malwarebytes

It is interesting how ransomware authors are going for Norse mythology as Sigrun means “victory rune” and is a valkyrie – a mythological angel-like creature. Nevertheless, authors of Sigrun ransomware are of Russian origin due to the fact that they try to avoid infecting Russian individuals.

Sigrun virus spreads via contaminated attachments in spam emails. Users who open the .txt, .pdf, .doc, .zip or other affixed file instantaneously download malware into their computers. It is then ready to start its malicious activities.

First, the crypto-virus modifies certain system files (including registry entries) to acquire boot persistence. This way, it can start-up every time Windows is launched. Next, it initiates a full system scan to find files to lock up. As soon it is complete, Sigrun malware encrypts data and executes the ransom notes to inform the user about the situation.

Various file types are targeted by the virus, including .txt, .doc, .html, .xlsx, .dat, .mp3, .jpg. .gif and similar. For example, the encoded file would look like this: picture.jpg.sigrun. The strong encryption algorithm is used for file encryption, and only a key can unlock them. These decryptors are usually stored on a remote server and are only accessible to hackers. Nevertheless, users should ignore the key – remove Sigrun ransomware first and then proceed with file recovery.

There are several files that the virus does not targets, including:

  • .sigrun
  • .admin
  • .dll
  • .sys
  • .exe
  • .ico
  • .key, etc.

Users are urged to contact criminals via the address. The size of ransom is unknown, and it seems like hackers communicate with the victim before agreeing on the size of the payment. It is typically demanded in Bitcoin or another popular cryptocurrency, like Monero or Ethereum. Victims are also offered the proof that decryption is possible – they can send Sigrun authors three files which they would decode for free.

Sigrun malwareSigrun ransomware is a file-encrypting virus that locks up all files and demands ransom for its release.

The note states the following:

Dear user, all your important files have been encrypted! Don’t worry! Your files still can be restored by us! In order to restore it you need to contact with us via e-mail.

As a proof we will decrypt 3 files for free! Please, attach this to your message:

As we already mentioned, cybercriminals should be ignored as they often do not provide the offered key. Besides, even if they do, they will know that you are susceptible to the demands and might contaminate your machine again in the future. Instead, reboot your PC in Safe Mode with Networking and take care of Sigrun removal. Security experts[2] suggest using ReimageIntego or SpyHunter 5Combo Cleaner for that task.

If you have a backup ready – you are lucky, as you can recover all your files without problems, as long as they are stored on a remote server and not connected to the contaminated machine. If you are not that prepared and didn’t use data backup, you might be in a bit of trouble. However, you can always try third-party tools that may help you with file recovery.

Hackers help Russian victims for free

Russian cybercriminals are known to avoid infecting Russian speaking individuals (including former USSR countries), as they are cautious of the authorities, who could target them if locals were involved.

When Sigrun is first executed, it checks for the keyboards layouts installed – “HKEY_CURRENT_USER\Keyboard Layout\Preload.” Once the virus finds Russian layout, it does not encrypt files and merely deletes itself. However, not all former USSR countries use Russian layout; therefore, those individuals can still get infected. Hackers also mentioned that they added a Ukranian layout to the list of exceptions.

While authors of Sigrun virus ask for as much as $2,500 in Dash or Bitcoin for file decryption, all Russian-speaking users have to do is email culprits and they offer their help for free.

Sigrun decryption for free

Avoid deadly ransomware viruses by deleting spam emails

The best practice is not to contaminate your machine with viruses in the first place. Of course, there will never be a guarantee as malware authors continually modify their code to improve avoidance and develop their malicious software distribution methods. However, there is something you can do. You can be more careful and attentive while browsing the internet.

First of all, we suggest using strong passwords for each of your accounts and change them regularly. Note that unprotected RDP configuration or weak password might be an easy way for hackers to infiltrate your machine with malware.

Next, you should not open spam emails carelessly. Malicious attachments often hide inside these emails, as well as cleverly-disguised hyperlinks may lead you to malicious payload execution. Therefore, if in doubt, make sure you delete the message even without looking at it. Beware that some criminals have decent social engineering skills[3] and are great at luring people with perfectly constructed phishing emails.

Finally, avoid suspicious websites, especially cracked software and other file-sharing sites. Additionally, do not click on questionable ads as they might lead you to malware-ridden sites.

Sigrun elimination procedure

Remember, you have to remove Sigrun ransomware before you proceed with file recovery. Otherwise, your data will be contaminated and locked-up again. If you have remote storage with a backup ready, do not connect it to your machine before you are sure that Sigrun virus is exterminated.

Ransomware viruses are serious threats and use sophisticated code. Thus, do not even try manual Sigrun removal as you will fail. Only trained professionals can execute that task. Instead, employ reputable security software, enter Safe Mode with Networking, and perform a full system scan. If you did not have a backup, check out the alternative file restoration methods below.

do it now!
Reimage Happiness
Intego Happiness
Compatible with Microsoft Windows Compatible with macOS
What to do if failed?
If you failed to fix virus damage using Reimage Intego, submit a question to our support team and provide as much details as possible.
Reimage Intego has a free limited scanner. Reimage Intego offers more through scan when you purchase its full version. When free scanner detects issues, you can fix them using free manual repairs or you can decide to purchase the full version in order to fix them automatically.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Reimage, try running SpyHunter 5.
Alternative Software
Different software has a different purpose. If you didn’t succeed in fixing corrupted files with Intego, try running Combo Cleaner.

Getting rid of Sigrun virus. Follow these steps

Manual removal using Safe Mode

To enter Safe Mode with Networking, follow these steps:

Important! →
Manual removal guide might be too complicated for regular computer users. It requires advanced IT knowledge to be performed correctly (if vital system files are removed or damaged, it might result in full Windows compromise), and it also might take hours to complete. Therefore, we highly advise using the automatic method provided above instead.

Step 1. Access Safe Mode with Networking

Manual malware removal should be best performed in the Safe Mode environment. 

Windows 7 / Vista / XP
  1. Click Start > Shutdown > Restart > OK.
  2. When your computer becomes active, start pressing F8 button (if that does not work, try F2, F12, Del, etc. – it all depends on your motherboard model) multiple times until you see the Advanced Boot Options window.
  3. Select Safe Mode with Networking from the list. Windows 7/XP
Windows 10 / Windows 8
  1. Right-click on Start button and select Settings.
  2. Scroll down to pick Update & Security.
    Update and security
  3. On the left side of the window, pick Recovery.
  4. Now scroll down to find Advanced Startup section.
  5. Click Restart now.
  6. Select Troubleshoot. Choose an option
  7. Go to Advanced options. Advanced options
  8. Select Startup Settings. Startup settings
  9. Press Restart.
  10. Now press 5 or click 5) Enable Safe Mode with Networking. Enable safe mode

Step 2. Shut down suspicious processes

Windows Task Manager is a useful tool that shows all the processes running in the background. If malware is running a process, you need to shut it down:

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Click on More details.
    Open task manager
  3. Scroll down to Background processes section, and look for anything suspicious.
  4. Right-click and select Open file location.
    Open file location
  5. Go back to the process, right-click and pick End Task.
    End task
  6. Delete the contents of the malicious folder.

Step 3. Check program Startup

  1. Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
  2. Go to Startup tab.
  3. Right-click on the suspicious program and pick Disable.

Step 4. Delete virus files

Malware-related files can be found in various places within your computer. Here are instructions that could help you find them:

  1. Type in Disk Cleanup in Windows search and press Enter.
    Disk cleanup
  2. Select the drive you want to clean (C: is your main drive by default and is likely to be the one that has malicious files in).
  3. Scroll through the Files to delete list and select the following:

    Temporary Internet Files
    Recycle Bin
    Temporary files

  4. Pick Clean up system files.
    Delete temp files
  5. You can also look for other malicious files hidden in the following folders (type these entries in Windows Search and press Enter):


After you are finished, reboot the PC in normal mode.

Remove Sigrun using System Restore

You can eliminate Sigrun using System Restore function:

  • Step 1: Reboot your computer to Safe Mode with Command Prompt
    Windows 7 / Vista / XP
    1. Click Start Shutdown Restart OK.
    2. When your computer becomes active, start pressing F8 multiple times until you see the Advanced Boot Options window.
    3. Select Command Prompt from the list Select 'Safe Mode with Command Prompt'

    Windows 10 / Windows 8
    1. Press the Power button at the Windows login screen. Now press and hold Shift, which is on your keyboard, and click Restart..
    2. Now select Troubleshoot Advanced options Startup Settings and finally press Restart.
    3. Once your computer becomes active, select Enable Safe Mode with Command Prompt in Startup Settings window. Select 'Enable Safe Mode with Command Prompt'
  • Step 2: Restore your system files and settings
    1. Once the Command Prompt window shows up, enter cd restore and click Enter. Enter 'cd restore' without quotes and press 'Enter'
    2. Now type rstrui.exe and press Enter again.. Enter 'rstrui.exe' without quotes and press 'Enter'
    3. When a new window shows up, click Next and select your restore point that is prior the infiltration of Sigrun. After doing that, click Next. When 'System Restore' window shows up, select 'Next' Select your restore point and click 'Next'
    4. Now click Yes to start system restore. Click 'Yes' and start system restore
    Once you restore your system to a previous date, download and scan your computer with ReimageIntego and make sure that Sigrun removal is performed successfully.

Bonus: Recover your data

Guide which is presented above is supposed to help you remove Sigrun from your computer. To recover your encrypted files, we recommend using a detailed guide prepared by security experts.

Do not contact cybercrooks, even if you do not have a backup ready. Instead, ignore their demands and follow alternative data recovery methods.

If your files are encrypted by Sigrun, you can use several methods to restore them:

Try Data Recovery Pro

This tool was created to restore broken or accidentally deleted files. Nevertheless, in some cases, this application might help users whose files are affected by ransomware.

  • Download Data Recovery Pro;
  • Follow the steps of Data Recovery Setup and install the program on your computer;
  • Launch it and scan your computer for files encrypted by Sigrun ransomware;
  • Restore them.

Windows Previous Versions Feature might be useful

You can only reclaim files one-by-one. Hence, large amount of data might not be recoverable. Additionally, for the feature to work, you should have had System Restore function enable before the attack occurred.

  • Find an encrypted file you need to restore and right-click on it;
  • Select “Properties” and go to “Previous versions” tab;
  • Here, check each of available copies of the file in “Folder versions”. You should select the version you want to recover and click “Restore”.

ShadowExplorer might be able to recover your data

If you are lucky enough and the virus did not delete shadow volume copies, you can recover all your files with this application.

  • Download Shadow Explorer (;
  • Follow a Shadow Explorer Setup Wizard and install this application on your computer;
  • Launch the program and go through the drop down menu on the top left corner to select the disk of your encrypted data. Check what folders are there;
  • Right-click on the folder you want to restore and select “Export”. You can also select where you want it to be stored.

There is no decryptor available yet

Finally, you should always think about the protection of crypto-ransomwares. In order to protect your computer from Sigrun and other ransomwares, use a reputable anti-spyware, such as ReimageIntego, SpyHunter 5Combo Cleaner or Malwarebytes

How to prevent from getting ransomware

Stream videos without limitations, no matter where you are

There are multiple parties that could find out almost anything about you by checking your online activity. While this is highly unlikely, advertisers and tech companies are constantly tracking you online. The first step to privacy should be a secure browser that focuses on tracker reduction to a minimum.

Even if you employ a secure browser, you will not be able to access websites that are restricted due to local government laws or other reasons. In other words, you may not be able to stream Disney+ or US-based Netflix in some countries. To bypass these restrictions, you can employ a powerful Private Internet Access VPN, which provides dedicated servers for torrenting and streaming, not slowing you down in the process.

Data backups are important – recover your lost files

Ransomware is one of the biggest threats to personal data. Once it is executed on a machine, it launches a sophisticated encryption algorithm that locks all your files, although it does not destroy them. The most common misconception is that anti-malware software can return files to their previous states. This is not true, however, and data remains locked after the malicious payload is deleted.

While regular data backups are the only secure method to recover your files after a ransomware attack, tools such as Data Recovery Pro can also be effective and restore at least some of your lost data.

About the author
Jake Doevan
Jake Doevan - Computer technology expert

If this free guide helped you and you are satisfied with our service, please consider making a donation to keep this service alive. Even a smallest amount will be appreciated.

Contact Jake Doevan
About the company Esolutions

Removal guides in other languages