Alka file extension
.Alka file extension is a file extension that is used by the 204th version of the STOP ransomware. Like other ransomware, Alka virus is created to encrypt the victim’s files, and then demand a ransom for decrypting them. Fortunately, a group of security researchers created a free decryptor. This decryptor can help virus victims decrypt .alka files. In addition to the decryptor, there are several more methods, each of which can help restore the contents of encrypted files. Read more about this, as well as how to remove Alka virus and protect your computer from such ransomware below.
Alka virus is new version of STOP (Djvu) ransomware. According to security researchers, this version is not much different from previous versions of STOP ransomware, such as Repp and Btos, which were discovered earlier. The ransomware virus is spread by websites offering to download freeware, key generators, activators, cracked games, torrents and so on.
Upon execution, Alka 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’).
Alka virus 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. Alka 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:
.crw, .zi, .zif, .xlk, .sid, .ztmp, .fos, .wsh, .epk, .zip, .vdf, .wbm, .vpk, .xdb, .svg, .odb, .xlsx, .layout, .rgss3a, .sidd, .sie, .xf, .sis, .slm, .mlx, .zdb, .1, .odc, .das, .yml, .itl, .z3d, .wp4, .x, .rim, .srf, .webdoc, .xwp, .2bp, .ntl, .w3x, .wp5, .x3f, .r3d, .lrf, .js, .jpg, .rtf, .psk, .x3d, .apk, .p7c, .snx, .gdb, .xls, .txt, .orf, .yal, .mp4, .doc, .csv, .m3u, .flv, .jpe, .xmmap, .wmv, .wmd, .big, .accdb, .blob, .xy3, .xlsm, .hplg, .ff, .3ds, .wpw, .xyp, .wpb, .pak, .arch00, .bar, .ws, .xyw, .wm, .avi, .wpd, .ncf, .wdb, .xdl, .hkx, .xlsx, .zip, .qic, .mrwref, .fpk, wallet, .pkpass, .pdd, .erf, .0, .css, .cdr, .dbf, .wsd, .db0, .iwi, .raf, .pdf, .xml, .fsh, .xls, .wot, .wri, .pptm, .wbk, .p12, .sr2, .qdf, .indd, .dng, .wbc, .wp7, .wma, .dazip, .lbf, .menu, .m2, .png, .ysp, .wmf, .dwg, .mpqge, .der, .iwd, .litemod, .bsa, .bc7, .xld, .x3f, .t12, .xlgc, .icxs, .zabw, .wcf, .ods, .wpa, .tax, .wps, .syncdb, .wgz, .wps, .bkp, .hkdb, .wpl, .raw, .kdc, .rwl, .asset, .wn, .wpt, .dxg, .kf, .3dm, .wire, .sum, .wpg, .mef, .ibank, .xxx, .odt, .cer, .mdbackup, .vcf, .upk, .mddata, .xbplate, .xlsb, .xll, .cr2, .vpp_pc, .docx, .zdc, .wpe, .vfs0, .itdb, .ppt, .itm, .p7b, .rar, .srw, .webp
Alka encrypts file-by-file. Each file that has been encrypted will be renamed, the .alka 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 Alka 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 Alka virus. 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.
|Type||Crypto malware, Crypto virus, File locker, Ransomware, Filecoder|
|Encrypted files extension||.alka|
|Ransom amount||$980, $490 in Bitcoins|
|Detection Names||Trojan.GenericKD.32980969, Trojan.Win32.Crypt, Trojan.Stop.ci, Trojan-Ransom.Win32.Stop.im, Trojan.Malware.74655711.susgen, GenericRXJN-JO!1B29BA23050C, Ransom:Win32/STOP.BS!MTB, Trojan.Kryptik!1.C0F7 (CLOUD), Win32.Trojan.Stop.Dxwz, Trojan.Stop.Win32.67|
|Symptoms||Documents, photos and music won’t open. Your documents, photos and music have a wrong name, suffix or extension, or don’t look right when you open them. Your file directories contain a ‘ransom note’ file that is usually a .html, .jpg or .txt file. ‘All files on your computer have been encrypted’ message on your desktop.|
|Distribution ways||Malicious links in emails. Drive-by downloading (when a user unknowingly visits an infected web-site and then malware is installed without the user’s knowledge). Social media posts (they can be used to entice users to download malicious software with a built-in ransomware downloader or click a suspicious link). USB sticks containing malware.|
|Removal||Alka virus removal guide|
|Decryption||Free Alka Decryptor|
How to remove Alka virus, Recover, Decrypt .alka files
Security researchers confirm the words of the authors of Alka virus. All files with the extension ‘.Alka’ are encrypted and thus cannot be read and used. The only way to decrypt them is to use the key and the decryptor. Fortunately, there is some good news. As we already reported above, Alka virus belongs to STOP ransomware family, which means that you can use the free decryptor created by Emsisoft to decrypt the encrypted files. Even if the decryptor does not help, there are some alternative ways that can help restore the contents of the encrypted files. To learn more about decrypting files, simply scroll down to section ‘How to decrypt .alka 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.
- How to remove Alka virus
- How to decrypt .alka files
- How to restore .alka files
- How to protect your computer from Alka crypto malware
How to remove Alka virus
Finding and removing ransomware components manually is very difficult, so we recommend using free malware removal tools. Moreover, it is desirable to use not one, but several utilities. Even if it seems to you that there is no ransomware on the computer, it does not mean anything. The virus may start encrypting the files again the next time you turn on or restart the computer. You must be completely sure that Alka has been removed, and also that there is no other malware on the computer. Below we provide a list of recommended tools with brief instructions.
Run Zemana Anti-Malware to remove Alka ransomware
Thinking about remove Alka ransomware virus from your machine? Then pay attention to Zemana Anti-Malware (ZAM). This is a well-known tool, originally created just to scan for and delete malware, trojans and worms. But by now it has seriously changed and can not only rid you of malicious software, but also protect your PC system from ransomware virus, malicious software and worms, as well as identify and uninstall common viruses and trojans.
Click the following link to download Zemana installer called Zemana.AntiMalware.Setup on the PC system. Save it to your Desktop.
Author: Zemana Ltd
Category: Security tools
Update: July 16, 2019
Start the installer after it has been downloaded successfully and then follow the prompts to setup this tool on your system.
During installation you can change certain settings, but we recommend you don’t make any changes to default settings.
When install is finished, this malware removal utility will automatically start and update itself. You will see its main window as shown below.
Now press the “Scan” button . Zemana Free application will scan through the whole personal computer for the Alka ransomware related folders,files and registry keys. A system scan can take anywhere from 5 to 30 minutes, depending on your PC. When a malware, adware or PUPs are detected, the count of the security threats will change accordingly.
As the scanning ends, the results are displayed in the scan report. When you are ready, press “Next” button.
The Zemana Anti-Malware will remove Alka virus related folders,files and registry keys and add items to the Quarantine. Once the process is done, you can be prompted to reboot your computer to make the change take effect.
Remove Alka with MalwareBytes AntiMalware (MBAM)
You can remove Alka ransomware virus automatically with a help of MalwareBytes AntiMalware. We recommend this free malware removal utility because it can easily delete ransomware, adware, malware and other unwanted applications with all their components such as files, folders and registry entries.
- MalwareBytes can be downloaded from the following link. Save it on your MS Windows desktop or in any other place.
Category: Security tools
Update: April 15, 2020
- When downloading is finished, close all applications and windows on your PC system. Open a file location. Double-click on the icon that’s named mb3-setup.
- Further, press Next button and follow the prompts.
- Once install is done, click the “Scan Now” button to perform a system scan for the Alka ransomware virus. This process can take quite a while, so please be patient. When a malicious software, adware or PUPs are found, the count of the security threats will change accordingly. Wait until the the checking is done.
- Once the scan is finished, a list of all items detected is produced. Make sure all threats have ‘checkmark’ and click “Quarantine Selected”. When that process is complete, you can be prompted to restart your PC system.
The following video offers a guidance on how to delete browser hijacker infections, adware and other malicious software with MalwareBytes.
Use Kaspersky virus removal tool to remove Alka virus
Kaspersky virus removal tool (KVRT) is free and easy to use. It can find and remove ransomware, spyware, adware, worms and other malware. KVRT is powerful enough to find and remove Alka virus registry entries and files that are hidden on the system.
Download Kaspersky virus removal tool (KVRT) from the link below. Save it on your Desktop.
Author: Kaspersky® lab
Category: Security tools
Update: March 5, 2018
After the download is finished, double-click on the KVRT icon. Once initialization process is finished, you will see the KVRT screen as displayed in the figure 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 look for Alka virus and other trojans and malicious programs. A system scan can take anywhere from 5 to 30 minutes, depending on your PC. While the KVRT program is checking, you can see how many objects it has identified as threat.
When finished, Kaspersky virus removal tool will open a list of found security threats as displayed in the figure below.
Next, you need to press on Continue to begin a cleaning task.
How to decrypt .alka files
As we already reported above, files with .alka extension are files that have been encrypted by Alka virus. Their contents will remain locked until decrypted using the decryptor and the key. Fortunately, there is a free decryptor that can decrypt .alka files. Below we provide instructions on where to download and how to use this decryptor.
To decrypt .alka files, use free STOP (alka) decryptor
- Download STOP (alka) decryptor 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.
Unfortunately, at the moment, this decryptor is able to decrypt only files encrypted with an offline key, as Emsisoft found a way to find this key. 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 find this key. Of course, the authors of Alka virus own this key, but we do not think that paying a ransom is the right way to decrypt .alka 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
Since STOP (Alka) decryptor only decrypts files encrypted with the offline key, each Alka’s victim needs to find out which key was used to encrypt the files. Determining the type of key used is not difficult. Below we give two ways. Use any of them.
Find out the type of 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 that starts with ‘0204’ – this is your personal id.
Find out the type of 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’, Alka 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.
What to do if STOP (Alka) decryptor says “Error: Unable to decrypt file with ID”
If during decryption of .Alka files the decryptor reports ‘Error: Unable to decrypt file with ID’, skips files without decrypting them, then two cases are possible why this happens:
- files are encrypted with an ‘online key’, in this case, you need to use alternative methods to restore the contents of encrypted files;
- files are encrypted with an ‘offline key’, but the key itself has not yet been found 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;
How to restore .alka files
As we mentioned above, in addition to using the free decryptor, 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 virus used an online key, and for the case when the virus 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 Alka virus is completely removed. To scan your computer for ransomware, use free malware removal tools.
Restore .alka encrypted files using Shadow Explorer
The Microsoft Windows has a feature called ‘Shadow Volume Copies’ that can help you to recover .alka 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.
First, click the link below, then click the ‘Download’ button in order to download the latest version of ShadowExplorer.
Category: Security tools
Update: September 15, 2019
Once the downloading process is finished, 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 displayed in the figure below.
Run the ShadowExplorer tool and then select the disk (1) and the date (2) that you wish to recover the shadow copy of file(s) encrypted by the Alka crypto malware as shown on the image 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.
Recover .alka files with PhotoRec
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 on your personal computer from the following link.
Category: Security tools
Update: March 1, 2018
After downloading is finished, open a directory in which you saved it. Right click to testdisk-7.0.win and select 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 Microsoft Windows. It will open a screen like below.
Choose a drive to recover such as the one below.
You will see a list of available partitions. Choose a partition that holds encrypted personal files as displayed in the figure below.
Press File Formats button and specify file types to recover. You can to enable or disable the recovery of certain file types. When this is complete, press OK button.
Next, press Browse button to select where restored files should be written, then click Search.
Count of recovered files is updated in real time. All restored photos, documents and music are written in a folder that you have selected on the previous step. You can to access the files even if the recovery process is not finished.
When the recovery is done, click on Quit button. Next, open the directory where restored files are stored. You will see a contents as shown in the following example.
All recovered files 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 recovered files by extension and/or date/time.
How to protect your computer from Alka crypto malware
Most antivirus software already have built-in protection system against the ransomware. Therefore, if your computer does not have an antivirus application, make sure you install it. As an extra protection, use the HitmanPro.Alert. HitmanPro.Alert is a small security tool. It can check the system integrity and alerts you when critical system functions are affected by malware. HitmanPro.Alert can detect, remove, and reverse ransomware effects.
Please go to the link below to download the latest version of HitmanPro Alert for Windows. Save it on your Desktop.
Category: Security tools
Update: March 6, 2019
Once the downloading process is complete, open the directory in which you saved it. You will see an icon like below.
Double click the HitmanPro.Alert desktop icon. When the utility is started, you’ll be displayed a window where you can choose a level of protection, as displayed in the figure below.
Now click the Install button to activate the protection.
This guide was created to help all victims of Alka ransomware virus. We tried to give answers to the following questions: how to remove ransomware; how to decrypt .alka files; how to recover files, if STOP (alka) decryptor does not help; what is an online key and what is an offline key. We hope that the information presented in this manual has helped you.
If you have questions, then write to us, leaving a comment below. If you need more help with Alka related issues, go to here.