What is Btos virus?
Btos virus is a ransomware that attacks the victim’s computer by encrypting files and demanding a ransom for decrypting them. The ransomware attack can lead to data loss and financial losses. Btos encrypts files, renames them by appending the .btos extension, and creates files named “_readme.txt” containing the ransom demand message. For example, a file named “document.docx” will be renamed to “document.docx.btos”, a “image.jpg” file to “image.jpg.btos”, “invoice.pdf” to “invoice.pdf.btos”, and so on.
- What is Btos virus?
- Remove Btos virus (ransomware)
- Decrypt .btos files
- Restore .btos files
- Video Guide
Btos ransomware is a variant of the STOP (Djvu) ransomware. It is spread by websites offering to download freeware, key generators, Windows/Office activators, hacked software, torrents and so on. Upon execution, Btos creates a folder in the Windows system directory where it places a copy of itself and changes some Windows settings so that it starts up every time the computer is restarted or turned on. The virus collects information about the victim’s computer and then tries to establish a connection with its command server (C&C). If the connection has been established, then it sends information about the infected computer to the server, and in response receives the encryption key (the so-called ‘online key’) and additional commands and malware that must be executed on the victim’s computer. If the virus could not establish a connection with its command server, then it uses a fixed key (the so-called ‘offline key’).
The Btos ransomware encrypts files using a strong encryption algorithm and a key (‘offline key’ or ‘online key’, as described above). The virus tries to encrypt as many files as possible, for this it only encrypts the first 154kb of the contents of each file and thus significantly speeds up the encryption process. Btos has the ability to encrypt files on all drives connected to the computer: internal hard drives, flash USB disks, network storage, and so on. It skips without encryption: files located in the Windows system directories, files with the extension .ini, .bat, .dll, .lnk, .sys and files with the name ‘_readme.txt’. The remaining files located on the victim’s computer can be encrypted. For example, the following file types may be the target of ransomware attack:
.hkdb, .rtf, .m4a, .wbm, .psk, .pptm, .xll, .pst, .icxs, .r3d, .lrf, .arw, .qdf, .zip, .zip, .css, .wsc, .txt, .jpeg, .pak, .dng, .pkpass, .rb, .wbk, .xx, .snx, .gho, .wbz, .wpa, .wp4, .hkx, .iwi, .wpb, .ppt, .nrw, .bkp, .desc, .js, .xlsm, .ws, .mdb, .xxx, .yal, .x3f, .lbf, .wsh, .wn, .3fr, .yml, .db0, .pef, .wp, .raf, .rgss3a, .vtf, .ods, .pdd, .orf, .wpl, .rofl, .wire, .xmind, .wbd, .hvpl, .wbc, .layout, .wmd, .y, .forge, .wcf, .arch00, .wpw, .wbmp, .xyp, .xlgc, .crw, .kf, .wotreplay, .wav, .x, .wp6, .wmo, .vfs0, .bc7, .bar, .py, .wot, .hplg, .wma, .ff, .cer, .cfr, .ai, .crt, .wps, .fpk, .indd, .z3d, .odb, .accdb, .dxg, .wp7, .lvl, .re4, .dba, .wri, .mef, .m3u, .ncf, .sb, .sis, .wp5, .wpd, .der, .pem, .flv, .tor, .zw, .dbf, .zabw, .docx, .1, .xlk, .sav, .rwl, .vpp_pc, .p7c, .raw, .3ds, .epk, .dmp, .mdf, .xwp, .m2, .bkf, .mddata, .sum, .iwd, .ztmp, .pptx, .xls, .mp4, .zdb, .bay, .rw2, .docm, .vcf, .p12, .wma, .syncdb, .vdf, .xy3, .psd, .1st, .slm, .mlx, .wmv, .bik, .png, .wdp, .bc6, .svg, .menu, .xdb, .xmmap, .asset, .xpm, .itl, .webp, .erf, .rim, .cas, .apk, .jpe, .odt, .x3f, .ibank, .wpe, .webdoc, .rar, .pdf, .fsh, .w3x, .wpd, .d3dbsp, .mov, .tax, .odp, .zif, .wb2, .xlsb, .upk, .xdl, .sql, .sie, .z, .csv, .kdc, .mrwref, .ptx, .ysp, .x3d, .ltx, .eps, .wpt, .sidn, .kdb, .7z, .litemod, .qic, .fos, .2bp, .blob, .p7b, .cdr, .jpg, .wpg, .bsa, .dwg
Btos encrypts file-by-file. Each file that has been encrypted will be renamed, the .btos extension will be added at the end of its name. Thus, it marks all encrypted files. In every directory where there is at least one encrypted file, the virus places a file named ‘_readme.txt’. The file contains a message from the Btos authors. An example of the contents of this file is given below.
This message says that all files on the computer are encrypted and the only way to decrypt them is to buy a key and a decryptor from the authors of the Btos ransomware. That is, criminals demand a ransom for unlocking the victim’s files. The size of the ransom is $980, but if the victim is ready to pay the ransom within 72 hours, then its size is halved to $490. Attackers offer victims to verify that encrypted files can be decrypted. To do this, the victim must send them a small file to one of the email addresses specified in the ‘_readme.txt’ file. Of course, it is obvious that a single decrypted file cannot guarantee that after paying the ransom, the criminals will provide the victim with a working key and decryptor.
The full text of the Btos ransom note is
Don’t worry, you can return all your files!
All your files like pictures, databases, documents and other important are encrypted with strongest encryption and unique key.
The only method of recovering files is to purchase decrypt tool and unique key for you.
This software will decrypt all your encrypted files.
What guarantees you have?
You can send one of your encrypted file from your PC and we decrypt it for free.
But we can decrypt only 1 file for free. File must not contain valuable information.
You can get and look video overview decrypt tool:
Price of private key and decrypt software is $980.
Discount 50% available if you contact us first 72 hours, that’s price for you is $490.
Please note that you’ll never restore your data without payment.
Check your e-mail “Spam” or “Junk” folder if you don’t get answer more than 6 hours.
To get this software you need write on our e-mail:
Reserve e-mail address to contact us:
Your personal ID:
As mentioned above, all files with the extension ‘.btos’ are encrypted and thus cannot be read and used. The only way to decrypt the files is to use the key and the decryptor. Fortunately, there is some good news. The Btos virus belongs to the STOP ransomware family, which means that you can use a ransomware decryptor created by Emsisoft that decrypts files encrypted by STOP Ransomware. Using this decryptor, victims can decrypt files encrypted with offline key. There are also several alternative methods that in some cases can help recover encrypted files. To learn more about decrypting files, simply scroll down to section ‘How to decrypt .btos files’. Read the entire manual carefully. To make it easier for you to follow the instructions, we recommend that you print it or open it on your smartphone.
|Name||Btos ransomware, Btos File Virus|
|Type||File locker, Crypto virus, Ransomware, Crypto malware, Filecoder|
|Ransom amount||$490 or $980in Bitcoins|
|Detection Names||PWSX-gen [Trj], Gen:Heur.Mint.Zard.52, W32/Kryptik.IBG.gen!Eldorado, Trojan.SmokeLoader, Trojan.Malware.300983.susgen, Trojan:Win32/RedLine.JAP!MTB, HEUR:Trojan.Win32.Scarsi.gen, BScope.Trojan.AET.281105, ML/PE-A + Troj/Krypt-SY|
|Symptoms||Personal files won’t open. Your personal files now have new extensions that end with something like .locked, .crypted or .cryptor. Files named such as ”, ‘READ-ME’, ‘_open me’, _DECRYPT YOUR FILES’ or ‘_Your files have been encrypted” in every folder with an encrypted file. Ransom demanding message on your desktop.|
|Distribution ways||Phishing email scam that attempts to scare users into acting impulsively. Drive-by downloading (when a user unknowingly visits an infected web page and then malware is installed without the user’s knowledge). Social media, such as web-based instant messaging applications. Malicious websites.|
|Removal||Btos ransomware removal guide|
|Decryption||Btos File Decrypt Tool|
How to remove Btos ransomware
You need to remove the Btos ransomware virus (its associated files and Windows registry entries) before proceeding to decrypt or restore encrypted files. This must be done since otherwise the ransomware may re-encrypt the restored files. You can stop the ransomware from working, as it is not difficult to do. Another option is to perform a full system scan using free malware removal tools capable of detecting and removing ransomware infection.
It is very important to scan the computer for malware, as security researchers found that spyware could be installed on the infected computer along with the Btos ransomware. Spyware is a very dangerous security threat as it is designed to steal the user’s personal information such as passwords, logins, contact details, etc. If you have any difficulty removing the Btos virus, then let us know in the comments, we will try to help you.
To remove Btos ransomware, follow the steps below:
Kill Btos virus
Press CTRL, ALT, DEL keys together.
Click Task Manager. Select the “Processes” tab, look for something suspicious that is the Btos ransomware then right-click it and select “End Task” or “End Process” option. If your Task Manager does not open or the Windows reports “Task manager has been disabled by your administrator”, then follow the guide: How to Fix Task manager has been disabled by your administrator.
It is not difficult to detect a process related to the Btos ransomware. When looking for a malicious process, pay attention to the process icon and its name. Most often, this ransomware has a process name in the following format: 4-characters.tmp.exe or 4-characters.exe. For example: 7533.tmp.exe, A4b1.exe, CD15.tmp.exe, 19b2.exe. The process name can also contain “(32 bit)”. If you do not find a process with a similar name in the list of processes, then most likely the Btos ransomware has finished working. But keep in mind, if you do not remove the ransomware autostart entries, as demonstrated below, and do not delete its file, then after a while it may start again, and if it finds unencrypted files, immediately encrypt them.
Disable Btos Start-Up
Select the “Start-Up” tab, look for something similar to the one shown in the example below, right click to it and select Disable.
Close Task Manager.
Delete Btos Task
Type “Task Scheduler” in the search bar. Click Task Scheduler app in the search results. Click “Task Scheduler Library” in the left panel. On the right panel, right-click to “Time Trigger Task” and select Delete.
Close Task Scheduler.
Remove Btos virus
Run Task Manager and select the “Start-Up” tab. Right click to the Btos ransomware Start-Up entry and select Open File Location as shown below.
A directory containing one file will open in front of you, this file is the Btos virus. It needs to be removed. If you try to delete it immediately, then you will not succeed, since this file is protected from deletion.
To delete this file, you need to do the following. Right-click on the file, select Properties. In the window that opens, select Security tab. Next, click the Advanced button below. A window will open as shown in the following example.
Click Disable inheritance. In the Block inheritance dialog box that opens, select the first item (Convert inherited permissions…) as shown below.
In the Permission entries list, select “Deny Everyone”, click Remove button and then OK. Close the file properties window. You should now be able to remove the Btos virus. Right-click on the file and select Delete.
Scan computer for malware
MalwareBytes Anti-Malware (MBAM) is an antimalware software that can help you remove Btos virus. MalwareBytes can be used to remove almost all the forms of malicious programs including ransomware, trojans, worms, adware, browser hijackers, potentially unwanted software and spyware. MalwareBytes has real-time protection that can defeat most malicious software and ransomware. Despite so many features, it does not reduce the performance of your computer. You can use MalwareBytes Anti-Malware with any other antivirus without any conflicts.
First, please go to the link below, then click the ‘Download’ button in order to download the latest version of MalwareBytes AntiMalware.
Category: Security tools
Update: April 15, 2020
When the downloading process is done, close all windows on your computer. Further, launch the file named MBSetup. If the “User Account Control” dialog box pops up like below, click the “Yes” button.
It will show the Setup wizard which will assist you install MalwareBytes on the computer. Follow the prompts and do not make any changes to default settings.
After the setup is complete successfully, press “Get Started” button. Then MalwareBytes AntiMalware will automatically run and you can see its main window such as the one below.
Next, click the “Scan” button for scanning your computer for the Btos ransomware and other security threats. A system scan can take anywhere from 5 to 30 minutes, depending on your computer. While the MalwareBytes program is scanning, you can see how many objects it has identified as threat.
When the scanning is done, the results are displayed in the scan report. In order to remove all threats, simply press “Quarantine” button.
MalwareBytes Anti-Malware will remove Btos virus related folders,files and registry keys and move the selected threats to the program’s quarantine. Once that process is done, you can be prompted to reboot your computer.
In order to be 100% sure that the computer no longer has the Btos virus, we recommend using the Kaspersky virus removal tool (KVRT). KVRT is a free removal tool that can be downloaded and use to delete crypto malware, adware, spyware, trojans, worms, potentially unwanted programs, malicious software and other security threats from your computer. You can run this utility to scan for threats even if you have an antivirus or any other security application.
Download Kaspersky virus removal tool (KVRT) on your MS Windows Desktop by clicking on the link below.
Author: Kaspersky® lab
Category: Security tools
Update: March 5, 2018
Once the download is done, double-click on the KVRT icon. Once initialization procedure is complete, you’ll see the Kaspersky virus removal tool screen as shown below.
Click Change Parameters and set a check near all your drives. Press OK to close the Parameters window. Next click Start scan button to begin scanning your personal computer for the Btos crypto virus . This task may take quite a while, so please be patient. While the KVRT is checking, you may see count of objects it has identified either as being malicious software.
When Kaspersky virus removal tool has finished scanning, you can check all threats detected on your PC system like below.
In order to remove all items, simply click on Continue to begin a cleaning procedure.
How to decrypt .btos files
As we already reported above, files with .btos extension are files that have been encrypted by the Btos ransomware. Their contents will remain locked until decrypted using the decryptor and the key. Fortunately, there is a free Btos File Decrypt Tool that can decrypt .btos files. Below we provide instructions on where to download and how to use this decryptor.
To decrypt .btos files, use Btos File Decrypt Tool
- Download Btos File Decrypt Tool from the following link.
STOP Djvu decryptor
- Scroll down to ‘New Djvu ransomware’ section.
- Click the download link and save the decrypt_STOPDjvu.exe file to your desktop.
- Run decrypt_STOPDjvu.exe, read the license terms and instructions.
- On the ‘Decryptor’ tab, using the ‘Add a folder’ button, add the directory or disk where the encrypted files are located.
- Click the ‘Decrypt’ button.
Btos File Decypt Tool is a free software that can decrypt files that were encrypted with an offline key, as Emsisoft found a way to determine this key. Unfortunately, files encrypted with an online key cannot yet be decrypted. The online key is unique to each infected computer, and at the moment there is no way to obtain this key. Of course, criminals have this key, but we do not think that paying a ransom is a way to decrypt .btos files. In the case when the files are encrypted with an online key, there is a chance to restore the encrypted files using alternative methods, which are described below.
How to find out which key was used to encrypt files
Below we will demonstrate how to find out the type of key with which files were encrypted. This is very important, since knowing the type of key you can understand if you can decrypt .btos files for free using the Btos File Decypt Tool. We recommend using the second method, as it is more accurate.
How to find out the type of a key using ‘_readme.txt’ file
- Open the ransom demand message (‘_readme.txt’ file).
- Scroll down to the end of the file.
- There you will see a line with the text ‘Your personal ID’.
- Below is a line of characters, this is your personal id.
How to find out the type of a key using ‘PersonalID.txt’ file
- Open disk C.
- Open directory ‘SystemID’.
- Open file named ‘PersonalID.txt’. This file lists ‘Personal ID’s that match the keys that the virus used to encrypt files.
The ‘Personal ID’ is not a key, it is an identifier related to a key that was used to encrypt files. If the ID ends with ‘t1’, then the files are encrypted with an offline key. If the ID does not end with ‘t1’, Btos virus used an online key. If you could not figure out how to determine which key was used to encrypt files, then we can help. Just write a request here or in the comments below.
Btos File Decrypt Tool : “No key for New Variant online ID”
If, when you try to decrypt .btos files, Btos File Decrypt Tool reports:
No key for New Variant online ID: *
Notice: this ID appears to be an online ID, decryption is impossible
It means that your files are encrypted with an ‘online key’ and their decryption is impossible, since only the Btos authors have the key necessary for decryption. In this case, you need to use alternative methods listed below to restore the contents of encrypted files.
Btos File Decrypt Tool : “No key for New Variant offline ID”
If, during decryption of .btos files, Btos File Decrypt Tool reports:
No key for New Variant offline ID: *t1
Notice: this ID appears be an offline ID, decryption MAY be possible in the future.
It means the following: your files are encrypted with an ‘offline key’, but the key itself has not yet been obtained by security researchers, in this case, you need to be patient and wait a while, in addition, you can also use alternative ways for recovering encrypted data.
If for some reason you were unable to decrypt the encrypted files, then We recommend to follow the news on our Facebook or YouTube channels. So you ‘ll know right away that it ‘s possible to decrypt .btos files.
This video step-by-step guide will demonstrate How to use STOP Djvu decryptor to Decrypt encrypted files.
How to restore .btos files
As we mentioned above, in addition to using the Btos File Decypt Tool, there are several more methods for recovering encrypted files. These methods do not require the use of a decryptor and a key, and therefore are suitable for all cases when the ransomware used an online key, and for the case when the ransomware used an offline key. It is very important to check your computer for malware before you try to recover encrypted files. You must be 100% sure that Btos virus is completely removed. To scan your computer for ransomware, use free malware removal tools.
Recover .btos files with ShadowExplorer
The Microsoft Windows has a feature called ‘Shadow Volume Copies’ that can help you to recover .btos files encrypted by the ransomware. A small tool called ShadowExplorer will allow you to easily access the Shadow copies and restore the encrypted files to their original state. Unfortunately, the ransomware can delete these Shadow copies before it starts encrypting files. Therefore, if ShadowExplorer did not help you, then try another method, which is given below.
ShadowExplorer can be downloaded from the following link. Save it on your Microsoft Windows desktop.
Category: Security tools
Update: September 15, 2019
After the download is done, open a directory in which you saved it. Right click to ShadowExplorer-0.9-portable and select Extract all. Follow the prompts. Next please open the ShadowExplorerPortable folder as on the image below.
Start the ShadowExplorer tool and then choose the disk (1) and the date (2) that you want to restore the shadow copy of file(s) encrypted by the Btos ransomware virus as displayed below.
Now navigate to the file or folder that you wish to recover. When ready right-click on it and press ‘Export’ button like below.
This video step-by-step guide will demonstrate How to recover encrypted files using Shadow Explorer.
Use PhotoRec to restore .btos files
The last chance to restore encrypted files to their original state is using data recovery tools. We recommend a program called PhotoRec. It has all the necessary functions to restore the contents of encrypted files. It helped many victims recover data when it seemed like there was no more hope.
Download PhotoRec by clicking on the link below. Save it on your Windows desktop.
Category: Security tools
Update: March 1, 2018
When the download is complete, open a directory in which you saved it. Right click to testdisk-7.0.win and choose Extract all. Follow the prompts. Next please open the testdisk-7.0 folder like the one below.
Double click on qphotorec_win to run PhotoRec for Windows. It will open a screen as displayed in the following example.
Choose a drive to recover as displayed on the screen below.
You will see a list of available partitions. Choose a partition that holds encrypted documents, photos and music as displayed on the screen below.
Click File Formats button and select file types to recover. You can to enable or disable the recovery of certain file types. When this is done, click OK button.
Next, click Browse button to choose where restored photos, documents and music should be written, then click Search. We strongly recommend that you save the recovered files to an external drive.
Count of restored files is updated in real time. All recovered files are written in a folder that you have selected on the previous step. You can to access the files even if the restore process is not finished.
When the restore is complete, click on Quit button. Next, open the directory where recovered photos, documents and music are stored. You will see a contents as on the image below.
All recovered photos, documents and music are written in recup_dir.1, recup_dir.2 … sub-directories. If you are searching for a specific file, then you can to sort your restored files by extension and/or date/time.
This video step-by-step guide will demonstrate How to recover encrypted files using PhotoRec.
How to protect your PC from Btos ransomware
Most antivirus applications already have built-in protection system against the crypto virus. Therefore, if your personal computer does not have an antivirus program, make sure you install it. As an extra protection, use the HitmanPro.Alert. All-in-all, HitmanPro.Alert is a fantastic tool to protect your computer from any ransomware. If ransomware is detected, then HitmanPro.Alert automatically neutralizes malware and restores the encrypted files. HitmanPro.Alert is compatible with all versions of Windows operating system from MS Windows XP to Windows 10.
First, click the link below, then click the ‘Download’ button in order to download the latest version of HitmanPro Alert.
Category: Security tools
Update: March 6, 2019
Once the download is finished, open the folder in which you saved it. You will see an icon like below.
Double click the HitmanPro.Alert desktop icon. After the tool is started, you’ll be displayed a window where you can choose a level of protection, as on the image below.
Now click the Install button to activate the protection.
The Myantispyware.com team has developed this guide to help the Btos ransomware victims. Here we have given answers to important questions: how to remove Btos virus, how to decrypt files, what are the alternative ways to recover encrypted files. We hope this tutorial helped you remove this ransomware and restore encrypted files to their original state.
If you have questions, then write to us, leaving a comment below. If you need more help with Btos related issues, go to here.