Sepsis Ransomware

Also Known As: Sepsis virus
Distribution: Low
Damage level: Severe

Sepsis ransomware removal instructions

What is Sepsis?

Sepsis is a ransomware-type virus discovered by MalwareHunterTeam. Immediately after infiltration, Sepsis encrypts most stored data and adds the ".[].SEPSIS" appendix to the name of each compromised file. For instance, "sample.jpg" is renamed to "sample.jpg.[].SEPSIS". Encrypted data immediately becomes unusable. Furthermore, following successful encryption, Sepsis opens a pop-up window that contains a ransom-demand message.

As usual, the message informs victims of the encryption and encourages them to contact cyber criminals via an email address provided. They then supposedly receive further payment and decryption instructions. It is currently unknown whether Sepsis uses symmetric or asymmetric cryptography - this information is not provided, however, a unique key (generated individually of each victim) is necessary to restore data. All keys are stored on a remote server controlled by cyber criminals and users are encouraged to purchase them. The cost is not specified. Users will receive this information via email and are able to attach up to five selected files (up to 10 MB in total, non-archived), which are decrypted and returned to the victim as a guarantee that decryption is possible. Bear in mind, however, that cyber criminals can never be trusted. Research shows that these people often ignore victims, once payments are submitted. Therefore, paying typically gives no positive result. For these reasons, you are strongly advised to ignore all requests to contact these people or submit any payments. Unfortunately, there are no tools capable of decrypting data compromised by Sepsis. The only solution is to restore everything from a backup.

Screenshot of a message encouraging users to pay a ransom to decrypt their compromised data:

Sepsis decrypt instructions

The Internet is full of ransomware-type viruses that share similarities with Sepsis. The list of examples includes (but is not limited to) CryptON, RansomAES, RSAUtil, and PSCrypt. All are developed by different cyber criminals, however, their behavior is identical - all encrypt data and make ransom demands. Be aware that most ransomware-type viruses have just two major differences: 1) size of ransom, and; 2) type of encryption algorithm used. Unfortunately, most employ cryptographies that generate unique decryption keys (for example, RSA, AES and similar). Therefore, unless the virus is not fully developed or has certain bugs/flaws (the key is hard-coded, stored locally or similar) decrypting data manually without involvement of developers (contacting these people is not recommended) is impossible. Ransomware presents a strong case for maintaining regular data backups, however, it is very important to store backups on a remote server (e.g., Cloud) or unplugged storage device (i.e., Flash drive, external hard drive or similar). If not, malware encrypts backups with regular files.

How did ransomware infect my computer?

To proliferate ransomware, developers often use spam emails (infectious attachments), third party software download sources, fake software updaters, and trojans. Malicious attachments often come in the format of JavaScript files or MS Office documents. Once opened, these files stealthily download and install malware. Unofficial download sources (free file hosting websites, freeware download websites, P2P networks, etc.) present malware as legitimate software, thereby tricking users into downloading and installing viruses. Fake software updaters exploit outdated software bugs/flaws or simply download and install malware rather than updates. Trojans are probably the simplest of all - they open "backdoors" for other viruses to infiltrate the system.

How to protect yourself from ransomware infections?

The main reasons for computer infections are poor knowledge and careless behavior. The key to safety is caution. Therefore, to prevent this situation, be very cautious when browsing the Internet. Think twice before opening email attachments. If the file seems irrelevant or has been received from a suspicious/unrecognizable email address, do not open it and delete the email immediately. Furthermore, we strongly advise you to avoid using third party download/installation tools, since they often include rogue apps. Software should be downloaded from official sources only, using direct download links. The same rule applies to updating software. Keep installed apps up-to-date, however, use implemented functions or tools provided by the official developer only. Having a legitimate anti-virus/anti-spyware suite installed and running is also paramount.

Text presented in Sepsis ransomware pop-up window:

Welcome to Sepsis Ransomware!
All your files have been encrypted!
All your files have been encrypted due to a security problem with your PC. If you want to restore them, write us to the e-mail
Write this ID in the title of your message 16E734E0
In case of no answer in 24 hours write us to theese
The price depends on how fast you write to us. You have to pay for decryption in Bitcoins. After payment we will send you the decryption tool that will decrypt all your files.
Free decryption as guarantee
Before paying you can send us up to 5 files for free decryption. The total size of files must be less than 10Mb (non archived), and files should not contain valuable information. (databases,backups, large excel sheets, etc.)
How to obtain Bitcoins
The easiest way to buy bitcoins is LocalBitcoins site. You have to register, click 'Buy bitcoins', and select the seller by payment method and price.
Also you can find other places to buy Bitcoins and beginners guide here:
Do not rename encrypted files.
Do not try to decrypt your data using third party software, it may cause permanent data loss.
Decryption of your files with the help of third parties may cause increased price (they add their fee to our) or you can become a victim of a scam.

Screenshot of files encrypted by Sepsis (".[].SEPSIS" extension):

Files encrypted by Sepsis

Update 19 June, 2018 - Michael Gillespie released a free decrypter for this ransomware. You can download it HERE.

Sepsis ransomware removal:

Instant automatic removal of Sepsis virus: Manual threat removal might be a lengthy and complicated process that requires advanced computer skills. Spyhunter is a professional automatic malware removal tool that is recommended to get rid of Sepsis virus. Download it by clicking the button below:
▼ DOWNLOAD Spyhunter By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.

Quick menu:

Step 1

Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.

Safe Mode with Networking

Video showing how to start Windows 7 in "Safe Mode with Networking":

Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button. Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.

Windows 8 Safe Mode with networking

Video showing how to start Windows 8 in "Safe Mode with Networking":

Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click "Restart" while holding "Shift" button on your keyboard. In the "choose an option" window click on the "Troubleshoot", next select "Advanced options". In the advanced options menu select "Startup Settings" and click on the "Restart" button. In the following window you should click the "F5" button on your keyboard. This will restart your operating system in safe mode with networking.

windows 10 safe mode with networking

Video showing how to start Windows 10 in "Safe Mode with Networking":

Step 2

Log in to the account infected with the Sepsis virus. Start your Internet browser and download a legitimate anti-spyware program. Update the anti-spyware software and start a full system scan. Remove all entries detected.

If you cannot start your computer in Safe Mode with Networking, try performing a System Restore.

Video showing how to remove ransomware virus using "Safe Mode with Command Prompt" and "System Restore":

1. During your computer start process, press the F8 key on your keyboard multiple times until the Windows Advanced Options menu appears, and then select Safe Mode with Command Prompt from the list and press ENTER.

Boot your computer in Safe Mode with Command Prompt

2. When Command Prompt mode loads, enter the following line: cd restore and press ENTER.

system restore using command prompt type cd restore

3. Next, type this line: rstrui.exe and press ENTER.

system restore using command prompt rstrui.exe

4. In the opened window, click "Next".

restore system files and settings

5. Select one of the available Restore Points and click "Next" (this will restore your computer system to an earlier time and date, prior to the Sepsis ransomware virus infiltrating your PC).

select a restore point

6. In the opened window, click "Yes".

run system restore

7. After restoring your computer to a previous date, download and scan your PC with recommended malware removal software to eliminate any remaining Sepsis ransomware files.

To restore individual files encrypted by this ransomware, try using Windows Previous Versions feature. This method is only effective if the System Restore function was enabled on an infected operating system. Note that some variants of Sepsis are known to remove Shadow Volume Copies of the files, so this method may not work on all computers.

To restore a file, right-click over it, go into Properties, and select the Previous Versions tab. If the relevant file has a Restore Point, select it and click the "Restore" button.

Restoring files encrypted by CryptoDefense

If you cannot start your computer in Safe Mode with Networking (or with Command Prompt), boot your computer using a rescue disk. Some variants of ransomware disable Safe Mode making its removal complicated. For this step, you require access to another computer.

To regain control of the files encrypted by Sepsis, you can also try using a program called Shadow Explorer. More information on how to use this program is available here.

shadow explorer screenshot

To protect your computer from file encryption ransomware such as this, use reputable antivirus and anti-spyware programs. As an extra protection method, you can use programs called HitmanPro.Alert and EasySync CryptoMonitor, which artificially implant group policy objects into the registry to block rogue programs such as Sepsis ransomware.

Note that Windows 10 Fall Creators Update includes a "Controlled Folder Access" feature that blocks ransomware attempts to encrypt your files. By default, this feature automatically protects files stored in the Documents, Pictures, Videos, Music, Favorites as well as Desktop folders.

Controll Folder Access

Windows 10 users should install this update to protect their data from ransomware attacks. Here is more information on how to get this update and add an additional protection layer from ransomware infections.

HitmanPro.Alert CryptoGuard - detects encryption of files and neutralises any attempts without need for user-intervention:

hitmanproalert ransomware prevention application

Malwarebytes Anti-Ransomware Beta uses advanced proactive technology that monitors ransomware activity and terminates it immediately - before reaching users' files:

malwarebytes anti-ransomware

  • The best way to avoid damage from ransomware infections is to maintain regular up-to-date backups. More information on online backup solutions and data recovery software Here.

Other tools known to remove Sepsis ransomware: