This article will aid you to remove Sigma ransomware completely. Follow the ransomware removal instructions given below in the article.
Sigma is a ransomware virus that encrypts your files. The Sigma virus displays a ransom note message stored in a file called ReadMe.html. You are demanded to pay 1000 US dollars in the Bitcoin cryptocurrency as a ransom to supposedly restore your data. Keep on reading below to see how you could try to potentially recover some of your files.
Threat Summary
| Name | Sigma |
| Type | Ransomware, Cryptovirus |
| Short Description | The ransomware encrypts files on your computer and demands a ransom sum to be paid in the Bitcoin cryptocurrency. |
| Symptoms | The ransomware will encrypt your files, and also put up a ransom note called ReadMe.html. |
| Distribution Method | Spam Emails, Email Attachments |
| Detection Tool |
See If Your System Has Been Affected by malware
Download
Malware Removal Tool
|
User Experience | Join Our Forum to Discuss Sigma. |
| Data Recovery Tool | Windows 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. |
Sigma Ransomware – Distribution
Sigma ransomware might distribute its infection with various methods. A payload dropper which initiates the malicious script for this ransomware is being spread around the World Wide Web, and researchers have gotten their hands on a malware sample. If that file lands on your computer system and you somehow execute it – your computer system will become infected. You can see the detections of such a file on the VirusTotal service right here:
Sigma ransomware might also distribute its payload file on social media and file-sharing services. Freeware which is found on the Web can be presented as helpful also be hiding the malicious script for the cryptovirus. Refrain from opening files right after you have downloaded them. You should first scan them with a security tool, while also checking their size and signatures for anything that seems out of the ordinary. You should read the tips for preventing ransomware found in the forum section.
Sigma Ransomware – Description
Sigma is a virus that encrypts your files and extorts you to pay a ransom to supposedly recover them. The ransomware seems very similar to the LockeR Ransomware virus.
The extortionists want you to pay in Bitcoin for the alleged restoration of your files.
The following domain which is hosted on the TOR network is associated with the Sigma ransomware:
- https://yowl2ugopitfzzwb(.)onion
Sigma ransomware might make entries in the Windows Registry to achieve persistence, and could launch or repress processes in a Windows environment. Such entries are typically designed in a way to launch the virus automatically with each start of the Windows Operating System.
That ransom note message is displayed after the encryption of your files is complete. It is inside a file named ReadMe.html and can be viewed from the following screenshot down here:
That note reads the following:
What has happened to my files ? Why i am seeing this ?
All of your files have been encrypted with RSA 2048 Encryption. Which means, you wont be able to open them or view them properly. It does NOT mean they are damaged.
Solution
Well its quite simple only we can decrypt your files because we hold your RSA 2048 private key. So you need to buy the special decryption software and your RSA private key from us if you ever want your files back. Once payment is made, you will be given a decrypter along with your private key , once you run that , All of your files will be unlocked and back to normal.
So there are 2 ways to do this either you wait for a miracle and get your price doubled or follow instructions below carefully and get back your all important files.
Payment procedure
Download a special browser called “TOR browser” and then open the given below link. Steps for the same are –
1. Go to https://www.torproject.org/download/download-easy.html.en to download the “TOR Browser“.
2. Click the purple button which says “Download TOR Browser”
3. Run the downloaded file, and install it.
4. Once installation is completed, run the TOR browser by clicking the icon on Desktop.
5. Now click “Connect button”, wait a few seconds. and the TOR browser will open.
6. Copy and paste the below link in the address bar of the TOR browser.https://yowl2ugopitfzzwb.onion
Now HIT “Enter”
7. Wait a few seconds. and site will open then enter your GUlD mentioned below and process.
The note of the Sigma ransomware states that your files are encrypted. You are demanded to pay 1,000 US dollars in the Bitcoin cryptocurrency and it will double after a deadline passes. However, you should NOT under any circumstances pay any ransom. Your files may not get recovered, and nobody could give you a guarantee for that. Moreover, giving money to cybercriminals will most likely motivate them to create more ransomware viruses or commit different criminal acts.
The screenshot below shows the payment page hosted on the TOR network:
HOME / LIVECHAT/ FAQ/FREE DECRYPTION (1)
Sigma Ransomware
Your documents, photos, databases and other important files have been encrypted
Your files were encrypted at Jan 1 1970 4:00 AM
To recover them you need the private key of the key pair used to encrypt them and the decryptor software.
You can buy both of them for $1000.00Within 7 days you can purchase this product at a special price: ≈ $1000
After 7 days the price of this product will increase up to: ≈ $2000
Final deadline is 08-01-2018 01:12:17 (after that you will loose your important files forever)
1) Register a bitcoin wallet.
Create a Bitcoin Wallet (we recommend Blockchain(.)info) or other wallets (click here)
2) Purchase the required amount of bitcoins.
There are several ways you can buy bitcoins, you can use bitcoin exchanges (click here), buy directly from people
selling near you (click here) or using a bitcoin ATM (click here)3) Send exactly $1000.00 to the address:
1Gra1DcSWUgFsiUtMCHJe6mnwKApWo4V7c
From that same page you can find the FAQ page which is shown down here:
Here is what that FAQ page reads:
Question: How can i decrypt my files after payment?
Answer: After payment, you can download the << Sigma Decryptor >> from your personal page. We guarantee that all your files will be decrypted!
Question: My files was infected more then month ago, can i still decrypt it with your software?
Answer: Yes, you can still decrypt your files after the payment we keep your keypair for 2 months then its gets delte automatically and its impossible to recover your files after that!
Question: I do have multiple computers infected is there any discount?
Answer: Please follow instructions mentioned on live chat page and connect with us we can negotiate for multiple computers
Question: So if i pay and get my files back am i secure in future from this ransomware ?
Answer: we sale special Immunity as low as 100$ more on top of the decrypter payment if you buy it , we add your machine GUID to our whitelist and in future your machine never ever get infected again for buying immunity please follow instructions mentioned on live chat page and connect with us !
To top it all off, below you can see the Desktop background which is changed from the Sigma ransomware:
The message on that picture is different than the ransom note and TOR pages, and reads this:
SIGMA RANSOMWARE
ATTENTION ALL YOUR DOCUMENTS, PHOTOS, DATABASES AM) OTHERE IMPORTANT FILES HAVE BEEN ENCRYPTED
*** PLEASE READ THIS MESSAGE CAREFULLY IF YOU EVER WANT YOUR FILES BACK ***
The only way to get back your files to normal is to receive the private key and decryption program
To receive the private key and decryption program we created files with complete instructions inside every folder of your computer
as we! as in your desktop named *README* please read it and follow
If you somehow can not find any *README* files at your PC, follow the instructions below
Download “Tor Browser” from https://www.torproject.org/ and install it
In the “Tor Browser” open your personal page and enter your id : C912609086DF04DD92BB45751A16121C
https://uh6r7smsyxtsb25w.onion/
Attention… this page is available via “Tor Browser” only
Sigma Ransomware – Encryption
There is not much known for the encryption process of the Sigma ransomware, except that the encryption algorithm used by the virus is RSA with 2048-bit ciphers and that files get encrypted with a random extension.
The targeted extensions of files which are sought to get encrypted are currently unknown and if a list is discovered, it will be posted here as the article gets updated. The files used most by users and which are probably encrypted are from the following categories:
- Audio files
- Video files
- Document files
- Image files
- Backup files
- Banking credentials, etc
The Sigma cryptovirus could be set to erase all the Shadow Volume Copies from the Windows operating system with the help of the following command:
→vssadmin.exe delete shadows /all /Quiet
If the above-stated command is executed that will make the encryption process more efficient. That is due to the fact that the command eliminates one of the prominent ways to restore your data. If your computer device was infected with this ransomware and your files are locked, read on through to find out how you could potentially restore your files back to normal.
Remove Sigma Ransomware and Restore Files
If your computer got infected with the Sigma 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.
Several computer victims that have been infected with the reason have actually paid the hackers. Following the payment that have received no decryptors or restore instructions which further backs up the fact that the ransom note is a scam. Victims of the virus are advised to follow our in-depth instructions.
- Step 1
- Step 2
- Step 3
- Step 4
- Step 5
Step 1: Scan for Sigma with SpyHunter Anti-Malware Tool
Ransomware Automatic Removal - Video Guide
Step 2: Uninstall Sigma and related malware from Windows
Here is a method in few easy steps that should be able to uninstall most programs. No matter if you are using Windows 10, 8, 7, Vista or XP, those steps will get the job done. Dragging the program or its folder to the recycle bin can be a very bad decision. If you do that, bits and pieces of the program are left behind, and that can lead to unstable work of your PC, errors with the file type associations and other unpleasant activities. The proper way to get a program off your computer is to Uninstall it. To do that:
Follow the instructions above and you will successfully delete most unwanted and malicious programs.
Step 3: Clean any registries, created by Sigma on your computer.
The usually targeted registries of Windows machines are the following:
- HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
You can access them by opening the Windows registry editor and deleting any values, created by Sigma there. This can happen by following the steps underneath:
Tip: To find a virus-created value, you can right-click on it and click "Modify" to see which file it is set to run. If this is the virus file location, remove the value.
Before starting "Step 4", please boot back into Normal mode, in case you are currently in Safe Mode.
This will enable you to install and use SpyHunter 5 successfully.
Step 4: Boot Your PC In Safe Mode to isolate and remove Sigma
Step 5: Try to Restore Files Encrypted by Sigma.
Method 1: Use STOP Decrypter by Emsisoft.
Not all variants of this ransomware can be decrypted for free, but we have added the decryptor used by researchers that is often updated with the variants which become eventually decrypted. You can try and decrypt your files using the instructions below, but if they do not work, then unfortunately your variant of the ransomware virus is not decryptable.
Follow the instructions below to use the Emsisoft decrypter and decrypt your files for free. You can download the Emsisoft decryption tool linked here and then follow the steps provided below:
1 Right-click on the decrypter and click on Run as Administrator as shown below:
2. Agree with the license terms:
3. Click on "Add Folder" and then add the folders where you want files decrypted as shown underneath:
4. Click on "Decrypt" and wait for your files to be decoded.
Note: Credit for the decryptor goes to Emsisoft researchers who have made the breakthrough with this virus.
Method 2: Use data recovery software
Ransomware infections and Sigma aim to encrypt your files using an encryption algorithm which may be very difficult to decrypt. This is why we have suggested a data recovery method that may help you go around direct decryption and try to restore your files. Bear in mind that this method may not be 100% effective but may also help you a little or a lot in different situations.
Simply click on the link and on the website menus on the top, choose Data Recovery - Data Recovery Wizard for Windows or Mac (depending on your OS), and then download and run the tool.
Sigma-FAQ
What is Sigma Ransomware?
Sigma is a ransomware infection - the malicious software that enters your computer silently and blocks either access to the computer itself or encrypt your files.
Many ransomware viruses use sophisticated encryption algorithms to make your files inaccessible. The goal of ransomware infections is to demand that you pay a ransom payment to get access to your files back.
What Does Sigma Ransomware Do?
Ransomware in general is a malicious software that is designed to block access to your computer or files until a ransom is paid.
Ransomware viruses can also damage your system, corrupt data and delete files, resulting in the permanent loss of important files.
How Does Sigma Infect?
Via several ways.Sigma Ransomware infects computers by being sent via phishing emails, containing virus attachment. This attachment is usually masked as an important document, like an invoice, bank document or even a plane ticket and it looks very convincing to users.
Another way you may become a victim of Sigma is if you download a fake installer, crack or patch from a low reputation website or if you click on a virus link. Many users report getting a ransomware infection by downloading torrents.
How to Open .Sigma files?
You can't without a decryptor. At this point, the .Sigma files are encrypted. You can only open them once they are decrypted using a specific decryption key for the particular algorithm.
What to Do If a Decryptor Does Not Work?
Do not panic, and backup the files. If a decryptor did not decrypt your .Sigma files successfully, then do not despair, because this virus is still new.
Can I Restore ".Sigma" Files?
Yes, sometimes files can be restored. We have suggested several file recovery methods that could work if you want to restore .Sigma files.
These methods are in no way 100% guaranteed that you will be able to get your files back. But if you have a backup, your chances of success are much greater.
How To Get Rid of Sigma Virus?
The safest way and the most efficient one for the removal of this ransomware infection is the use a professional anti-malware program.
It will scan for and locate Sigma ransomware and then remove it without causing any additional harm to your important .Sigma files.
Can I Report Ransomware to Authorities?
In case your computer got infected with a ransomware infection, you can report it to the local Police departments. It can help authorities worldwide track and determine the perpetrators behind the virus that has infected your computer.
Below, we have prepared a list with government websites, where you can file a report in case you are a victim of a cybercrime:
Cyber-security authorities, responsible for handling ransomware attack reports in different regions all over the world:
Germany - Offizielles Portal der deutschen Polizei
United States - IC3 Internet Crime Complaint Centre
United Kingdom - Action Fraud Police
France - Ministère de l'Intérieur
Italy - Polizia Di Stato
Spain - Policía Nacional
Netherlands - Politie
Poland - Policja
Portugal - Polícia Judiciária
Greece - Cyber Crime Unit (Hellenic Police)
India - Mumbai Police - CyberCrime Investigation Cell
Australia - Australian High Tech Crime Center
Reports may be responded to in different timeframes, depending on your local authorities.
Can You Stop Ransomware from Encrypting Your Files?
Yes, you can prevent ransomware. The best way to do this is to ensure your computer system is updated with the latest security patches, use a reputable anti-malware program and firewall, backup your important files frequently, and avoid clicking on malicious links or downloading unknown files.
Can Sigma Ransomware Steal Your Data?
Yes, in most cases ransomware will steal your information. It is a form of malware that steals data from a user's computer, encrypts it, and then demands a ransom in order to decrypt it.
In many cases, the malware authors or attackers will threaten to delete the data or publish it online unless the ransom is paid.
Can Ransomware Infect WiFi?
Yes, ransomware can infect WiFi networks, as malicious actors can use it to gain control of the network, steal confidential data, and lock out users. If a ransomware attack is successful, it could lead to a loss of service and/or data, and in some cases, financial losses.
Should I Pay Ransomware?
No, you should not pay ransomware extortionists. Paying them only encourages criminals and does not guarantee that the files or data will be restored. The better approach is to have a secure backup of important data and be vigilant about security in the first place.
What Happens If I Don't Pay Ransom?
If you don't pay the ransom, the hackers may still have access to your computer, data, or files and may continue to threaten to expose or delete them, or even use them to commit cybercrimes. In some cases, they may even continue to demand additional ransom payments.
Can a Ransomware Attack Be Detected?
Yes, ransomware can be detected. Anti-malware software and other advanced security tools can detect ransomware and alert the user when it is present on a machine.
It is important to stay up-to-date on the latest security measures and to keep security software updated to ensure ransomware can be detected and prevented.
Do Ransomware Criminals Get Caught?
Yes, ransomware criminals do get caught. Law enforcement agencies, such as the FBI, Interpol and others have been successful in tracking down and prosecuting ransomware criminals in the US and other countries. As ransomware threats continue to increase, so does the enforcement activity.
About the Sigma Research
The content we publish on SensorsTechForum.com, this Sigma how-to removal guide included, is the outcome of extensive research, hard work and our team’s devotion to help you remove the specific malware and restore your encrypted files.
How did we conduct the research on this ransomware?
Our research is based on an independent investigation. We are in contact with independent security researchers, and as such, we receive daily updates on the latest malware and ransomware definitions.
Furthermore, the research behind the Sigma ransomware threat is backed with VirusTotal and the NoMoreRansom project.
To better understand the ransomware threat, please refer to the following articles which provide knowledgeable details.
As a site that has been dedicated to providing free removal instructions for ransomware and malware since 2014, SensorsTechForum’s recommendation is to only pay attention to trustworthy sources.
How to recognize trustworthy sources:
- Always check "About Us" web page.
- Profile of the content creator.
- Make sure that real people are behind the site and not fake names and profiles.
- Verify Facebook, LinkedIn and Twitter personal profiles.