Sigma Ransomware Virus Removal (+File Recovery) May 2018 Update

The encrypted files may not be the only damage done to you. parasite may still be hiding on your PC. To determine whether you've been infected with ransomware, we recommend downloading SpyHunter.

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More information on SpyHunter, steps to uninstallEULAThreat Assessment Criteria, and Privacy Policy.

This page aims to help you remove Sigma Ransomware for free. Our instructions also cover how any Sigma file can be recovered.

This article is designed to discuss the characteristic features of a program called Sigma. This program is a part of the Ransomware group of viruses, and is really harmful. What Sigma Ransomware actually does is it makes some of your most important files inaccessible to you by encrypting them and afterwards asking you for a ransom in return for access the encoded files.

What is Ransomware in general? Characteristic features and subcategories:

It is known that Ransomware originated in the late 20th century, allegedly in Russia. This terribly dangerous group of malware consists of several subtypes, such as the screen-blocking version, the most famous file-encryption subcategory, the mobile subtype, the type used by government bodies. Whatever subfamily a Ransomware virus belongs to, it may have brought a Trojan horse along with itself to let it inside your PC. The Trojan horse is the virus securing the passage for programs such as Sigma Ransomware by finding and using a vulnerability inside your system or any of the installed programs into it. These two awfully malicious programs may be found together in spam – attachments such as images, folders, documents and the emails themselves could be sources of this terrible duo. Here’s another general fact: what all of the Ransomware types we know of have in common is their ability to awfully harass the victim user.:

  • Screen-blocking Ransomware: such programs don’t really make any data inaccessible to you. It is just that they block your screen and produce a false alert covering the entire monitor, which tells you that you have to pay for accessing your “hijacked” data again. But in reality no file-encryption process really takes place, you are simply prevented from accessing anything by the giant full-screen banner.
  • The most common FILE-ENCRYPTION subcategory that Sigma Ransomware falls into: the programs from this subfamily really encrypt files. First of all, they define which data you regularly use and then all of that data gets encrypted with a key, consisting of two parts. Normally, the hackers give you one of the key components, however, demand a ransom for the other component via a notification that appears on your monitor right  after the encryption of all the predetermined data has been completed.

Sigma Ransomware Removal


Some of the steps will likely require you to exit the page. Bookmark it for later reference.

Reboot in Safe Mode (use this guide if you don’t know how to do it).



We get asked this a lot, so we are putting it here: Removing parasite manually may take hours and damage your system in the process. We recommend downloading SpyHunter to see if it can detect parasite files for you.

Press CTRL + SHIFT + ESC at the same time and go to the Processes Tab. Try to determine which processes are dangerous. 


Right click on each of them and select Open File Location. Then scan the files with our free online virus scanner:

Drag and Drop Files Here to Scan
Maximum file size: 128MB.

This scanner is free and will always remain free for our website's users. You can find its full-page version at: https://howtoremove.guide/online-virus-scanner/

Scan Results

Virus Scanner Result

After you open their folder, end the processes that are infected, then delete their folders. 

After you open their folder, end the processes that are infected, then delete their folders. 

Note: If you are sure something is part of the infection – delete it, even if the scanner doesn’t flag it. No anti-virus program can detect all infections.


Hold the Start Key and R –  copy + paste the following and click OK:

notepad %windir%/system32/Drivers/etc/hosts

A new file will open. If you are hacked, there will be a bunch of other IPs connected to you at the bottom. Look at the image below:

hosts_opt (1)

If there are suspicious IPs below “Localhost” – write to us in the comments.

Type msconfig in the search field and hit enter. A window will pop-up:


Go in Startup —> Uncheck entries that have “Unknown” as Manufacturer.

  • Please note that ransomware may even include a fake Manufacturer name to its process. Make sure you check out every process here is legitimate.


To remove parasite on your own, you may have to meddle with system files and registries. If you were to do this, you need to be extremely careful, because you may damage your system.

If you want to avoid the risk, we recommend downloading SpyHunter
a professional malware removal tool.

More information on SpyHunter, steps to uninstallEULAThreat Assessment Criteria, and Privacy Policy.

Type Regedit in the windows search field and press EnterOnce inside, press CTRL and F together and type the virus’s Name. 

Search for the ransomware  in your registries and delete the entries. Be extremely careful –  you can damage your system if you delete entries not related to the ransomware.

Type each of the following in the Windows Search Field:

  1. %AppData%
  2. %LocalAppData%
  3. %ProgramData%
  4. %WinDir%
  5. %Temp%

Delete everything in Temp. The rest just check out for anything recently added. Remember to leave us a comment if you run into any trouble!


How to Decrypt Sigma Ransomware files

We have a comprehensive (and daily updated) guide on how to decrypt your files. Check it out here.

If the guide doesn’t help, download the anti-virus program we recommended or try our free online virus scanner. Also, you can always ask us in the comments for help!

  • Mobile Ransomware versions usually affect the users of smartphones and other portable devices such as tablets. They work in the same way as the screen-blocking type: they make the device’s screen inaccessible to the victim users and after that request the payment of a ransom.
  • Some legal viruses based on Ransomware are exploited by certain government bodies for the purpose of persuading online criminals, violating the law in some way, to face their punishment. For example, such a legally operated virus might lock up the screen of the hacker and demand that they pay a fine for not complying with a given law.

How can you possibly deal with Sigma Ransomware?

A successful end of the entire unpleasant situation may come from implementing the steps inside our Removal Guide (just below). It could also result from using a specialized version of software, or asking a professional to remove the virus. What you should know is that in all the cases, your encrypted files will be in great danger. You might never get the opportunity to use them again especially provided that you don’t comply with the demands of the cyber criminals. Moreover, you might never access these files again, even if you provide the required ransom. Both decisions are risky, so make an informed choice.

The only efficient tool against Ransomware:

The only indeed helpful instrument against Ransomware seems to be prevention. Prevention in terms of staying away from a malware infection may be more general. We are going to share both kinds of advice with you below:

    • Ransomware targets files. So make sure to keep copies of all the data that really matters. In this way no online criminal will ever be able to blackmail you and disturb you in any way.
    • Ransomware comes from contagious letters from your electronic mail. Do not open any suspicious ones. Also, avoid their shady-looking attachments.
    • Malware makers really love it when you are not cautious while browsing the web. Prove the hackers wrong and stay particularly careful.
    • The version of your anti-virus app also matters. Purchase the best! Be selective.


Name Sigma
Type Ransomware
Danger Level High (Ransomware is by far the worst threat you can encounter)
Symptoms Very few and unnoticeable ones before the ransom notification comes up.
Distribution Method From fake ads and fake system requests to spam emails and contagious web pages.
Data Recovery Tool Currently Unavailable
Detection Tool

Keep in mind, SpyHunter’s malware detection tool is free. To remove the infection, you’ll need to purchase the full version. More information about SpyHunter and steps to uninstall.

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