The virus has appeared which uses a very strong encryption to encode files of infected computers. The virus is known as BitStak Ransomware, and it demands from affected users to make a payoff of roughly 50 US dollars in BitCoins (~0.08BTC). All users who have been affected by the BitStak Ransomware, are strongly advised not to pay any ransom money and instead focus on removing this malware from their computers. A preferable way for removal and file restoration you will find if you read this article thoroughly.
Threat Summary
| Name | BitStak |
| Type | Ransomware |
| Short Description | The malware encrypts users’ files asking the sum of approximately 50 US dollars for decryption. |
| Symptoms | The user may witness ransom message set as a wallpaper. Files no longer accessible with changed names and an added .bitstak file extension to them. |
| Distribution Method | Via an Exploit kit, drive-by download or a malicious JavaScript |
| Detection Tool | See If Your System Has Been Affected by BitStak Download Malware Removal Tool |
| User Experience | Join our forum to Discuss BitStak Ransomware. |
| 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. |
BitStak Ransomware – Spreading Methods
To be redistributed and infect as many user PCs as possible, BitStak Ransomware may use spam e-mails that may have different malicious tools. One strategy is to have malicious web links which can redirect to unsafe sites that may cause the infection via a drive-by download. Another version is if the spam e-mail has a malicious e-mail attachment which may contain either a malicious JavaScript or a malicious Exploit Kit that can infect the victim’s computer. Usually, the malicious files may be downloaded via an obfuscated program, which is concealed from various antivirus programs that may reside on the victim’s computer. This is why some attachments of BitStak Ransomware may be in archives as well.
BitStak Ransomware – Activity Overview
As soon as it has been activated on the victim’s PC, BitStak may create a malicious executable that may have different names and be situated in key Windows directories, for example:
After creating its malicious executable(s), BitStak may use the Windows Registry Editor to add malicious registry entries in it. This may be done for the virus to run on Windows boot and start encrypting files. The following keys may be targeted by BitStak:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
As soon as it runs on startup, BitStak Ransomware may target the following folders for encryption:
- %Program Files%
- %Program Files (x86)%
- %AppData%
- %Roaming%
- %Documents%
- %Downloads%
- %Videos%
- %Music%
- %Pictures%
- %Desktop%
BitStak Ransomware has also been reported to detect and encrypt every file of the following type, if existing:
Not only this, but BitStak Ransomware also adds the .bitstak file extension and in addition to that changes the names of the encrypted files with alpha-numerical sequence, for example, if the original file is New Text Document.txt, the encrypted file is Z8932h3.bitstak
After doing this, BitStak uses a picture which it may set as a wallpaper on the infected machine. The picture has the following ransom message:
→ “Your all files are locked and encrypted with a strong encryption method. You cannot get your files back without paying. We expect you to make a payment in 3 days, or your files will be permanently deleted.
Your all files are locked. To release your files, you need to pay 40(eur) fee using Bitcoin as a payment method. If you have any external hard-drives plugged, remember to plug them before restoring or you won’t be able to restore them later.
Amount
40.00 EUR / 0.07867 BTC or…
45.464 USD / 0.07867 BTC
Bitcoin Address
{cyber-criminals-bitcoin-address-here}
Or pay with Blockchain mobile app…
Verify your payment so you can get your files back.
Already paid? Verify now to restore your files.”
This is one of the few ransomware viruses that allow payment via a Blockchain mobile app. This is very clever because the payment is faster and easier as well. Cyber-criminals behind BlockChain Ransomware have really thought this through. Despite the offer, we strongly advise you not to pay the ransom fee and read our proposals for removal and file restoration below.
BitStak Ransomware – Removal and File Restoration
To remove BitStak, we advise you to use the instructions below. They are divided on manual and automatically based on how much experience you have with the removal of malware. In any case, we advise you to use the Automatic options, because for obvious reasons:
- It will remove other malware as well.
- All BitStak files and registry entries will be detected and permanently removed without any damage to the encrypted files.
- Your PC should be protected in the future from threats and unwanted programs and e-mails.
If you wish to restore your files, encrypted by BitStak for the moment decryptor has not been released. However, be advised that waiting for a decryptor to be developed by researchers is a way better choice than paying any ransom money to criminals and supporting their malicious activity this way. In the mean time we also advise you to check for backups, try system restore and data restoration software as well as Kaspersky’s free decryptors as well. You can find instructions for them if you check step “3. Restore files encrypted by BitStak” below.
