How to remove Aabn ransomware, Decrypt .aabn files.

What is Aabn virus?

Aabn virus is a ransomware that encrypts files such as videos, documents and demands ransom from users to decrypt their files. Aabn uses a strong encryption algorithm to encrypt files on fixed, removable, and network drives, renames the files by appending the .aabn 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.aabn”, a “image.jpg” file to “image.jpg.aabn”, “invoice.pdf” to “invoice.pdf.aabn”, and so on.

QUICK LINKS

• What is Aabn virus?
• Remove Aabn virus (ransomware)
• Decrypt .aabn files
• Restore .aabn files
• Video Guide

Aabn ransomware in detail

Aabn ransomware is a new variant of the STOP (djvu) ransomware. It infects the computer when the user downloads or runs malware infected files. Criminals lure unwary users into downloading ransomware by hiding malicious code within cracked versions of paid software, torrents, free software, key generators, and so on. Upon execution, an instance of Aabn virus is installed on victim’s computer.

Once installed on a computer, Aabn ransomware 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. 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’), 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 Aabn ransomware virus encrypts files using a strong encryption algorithm and a key (‘offline key’ or ‘online key’, as described above). It 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. Aabn 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:

.0, .wpd, .pst, .lvl, .apk, .itl, .bc6, .ai, .xyw, .wpl, .pfx, .1, .wpg, .sql, .w3x, .css, .ntl, .sie, .pak, .snx, .wpb, .wp7, .x3f, .wbk, .zip, .xdl, .doc, .xmind, .xy3, .vcf, .xf, .webp, .ws, .psk, .dbf, .vpp_pc, .sav, .wps, .vtf, .big, .xld, .xll, .raw, .der, .sid, .icxs, .hkx, .wbm, .7z, .x, .xls, .crt, .xyp, .menu, .tax, .psd, .dwg, .eps, .yal, wallet, .lrf, .rim, .x3d, .kdb, .js, .yml, .wgz, .rofl, .layout, .rwl, .x3f, .syncdb, .wsd, .hkdb, .3dm, .wmd, .sis, .dxg, .webdoc, .z3d, .cfr, .y, .docm, .fpk, .wmv, .srw, .wmo, .r3d, .accdb, .wn, .itm, .wm, .itdb, .db0, .wbc, .srf, .kf, .sum, .wp5, .sidd, .z, .cer, .qic, .mpqge, .ztmp, .cr2, .wbd, .2bp, .mp4, .m3u, .wbz, .jpg, .py, .ysp, .wpt, .xpm, .epk, .pef, .xwp, .wotreplay, .bsa, .d3dbsp, .vdf, .xdb, .wmv, .mcmeta, .arw, .zdc, .wsh, .m2, .crw, .zip, .zdb, .wp4, .re4, .wp6, .1st, .bkf, .xar, .mef, .forge, .desc, .xml, .ltx, .3fr, .dba, .xlsb, .map, .gdb, .erf, .wpe, .zabw, .xmmap, .ibank, .jpe, .xlgc, .odc, .bc7, .3ds, .svg, .xlsm, .ppt, .hplg, .wma, .dmp, .pkpass, .vpk, .jpeg, .odm, .xlk, .gho, .sidn, .wot, .p12, .docx, .orf, .wpw, .wav, .pptm, .slm, .xbplate, .mrwref, .asset, .vfs0, .txt, .pptx, .cdr, .upk, .xlsx, .png, .odp, .wp, .rtf, .xls, .fsh, .wcf

The Aabn ransomware encrypts file-by-file. Each file that has been encrypted will be renamed, the .aabn 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 Aabn 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 purchase a key and a decryptor from the Aabn authors. 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.

Text presented in the ransomnote:

ATTENTION!

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:
https://we.tl/t-4Xcf4IX21n
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:
support@bestyourmail.ch

Reserve e-mail address to contact us:
datarestorehelp@airmail.cc

Your personal ID:
0565xxxxxxxx

Security researchers confirm that all files with the extension ‘.aabn’ are encrypted and 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. As we already reported above, Aabn belongs to the STOP (djvu) 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 .aabn 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.

Threat Summary

Name	Aabn ransomware, Aabn file virus
Type	Crypto malware, Crypto virus, Filecoder, Ransomware, File locker
File extension	.aabn
Ransom note	_readme.txt
Contact	support@bestyourmail.ch, datarestorehelp@airmail.cc
Ransom amount	$980 or $490 in Bitcoins
Detection Names	Ransomware/Win.Stop.R29838, Trojan/Generic.ASMalwS.50F, Trojan.PWS.Stealer.3377, Trojan.Ransom.CEW, Win32:RansomX-gen [Ransom], Win.Ransomware.Bandook-9859375-1, W32/Ransom.PX.gen!Eldorado, Trojan-Ransom.Stop, Trojan.Win32.Stop.gcqxmm, BehavesLike.Win32.Dropper.thTrojan.Win32.Filecoder.xa
Symptoms	When you try to open your file, Windows notifies that you do not have permission to open this file. Your personal files now have different extensions that end with something like .locked, .crypted or .cryptor. Files named such as ”, ‘#_README_#’, ‘_DECRYPT_’ or ‘recover’ in each folder with at least one encrypted file.. You have received instructions for paying the ransom.
Distribution methods	Malicious e-mail spam. Drive-by downloads from a compromised website. Social media posts (they can be used to trick users to download malicious software with a built-in ransomware downloader or click a malicious link). Cybercriminals use misleading ads to distribute malware with no user interaction required.
Removal	Aabn ransomware removal guide
Decryption	Aabn File Decrypt Tool

How to remove Aabn virus (ransomware)

Before you start decrypting or recovering .aabn files, you need to remove the Aabn autostart entries. 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 Aabn 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 Aabn virus, then let us know in the comments, we will try to help you.

To remove Aabn ransomware, follow the steps below:

1. Kill Aabn virus
2. Disable Aabn startup
3. Delete Aabn task
4. Remove Aabn virus

Kill Aabn virus

Press CTRL, ALT, DEL keys together.

Click Task Manager. Select the “Processes” tab, look for something suspicious that is the Aabn 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 Aabn 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 Aabn 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 Aabn startup

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 Aabn 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 Aabn virus

Run Task Manager and select the “Start-Up” tab. Right click to the Aabn 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 Aabn 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 Aabn virus. Right-click on the file and select Delete.

Scan computer for malware

We advise using MalwareBytes AntiMalware. You can download and install MalwareBytes to detect and remove Aabn ransomware from your computer. One of the biggest advantages of using MalwareBytes is that is easy to use and is free. Also, it constantly keeps updating its virus/malware signatures DB. Let’s see how to install and scan your computer in order to remove Aabn from the system.

MalwareBytes can be downloaded from the following link. Save it on your Desktop.

After the downloading process is complete, close all programs and windows on your PC. Double-click the install file named MBSetup. If the “User Account Control” dialog box pops up as displayed in the figure below, click the “Yes” button.

It will open the Setup wizard which will help you setup MalwareBytes on your personal computer. Follow the prompts and don’t make any changes to default settings.

Once the install is done successfully, press “Get Started” button. MalwareBytes AntiMalware will automatically start and you can see its main screen as shown on the image below.

Now press the “Scan” button to scan your computer for ransomware, spyware, worms, trojans and other malicious software. During the scan MalwareBytes will locate security threats exist on your computer.

Once the scan is done, the results are displayed in the scan report. Review the scan results and then press “Quarantine” button. MalwareBytes will remove Aabn related folders,files and registry keys and move the selected threats to the program’s quarantine. When finished, you may be prompted to restart the computer.

In order to be 100% sure that the computer no longer has the Aabn ransomware virus, we recommend using the Kaspersky virus removal tool (KVRT). It can detect and remove ransomware, spyware, potentially unwanted programs, worms, trojans, adware software and other malware. KVRT is powerful enough to find and remove malicious registry entries and files that are hidden on the PC system.

Download Kaspersky virus removal tool on your computer by clicking on the following link.

Once the downloading process is done, double-click on the KVRT icon. Once initialization process is finished, 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 perform a system scan for the Aabn ransomware virus. While the utility is checking, you may see how many objects and files has already scanned.

After the system scan is done, you can check all threats detected on your PC as shown in the following example.

Next, you need to click on Continue to begin a cleaning process.

How to decrypt .aabn files

As we already reported above, files with .aabn extension are files that have been encrypted by the Aabn ransomware virus. Their contents will remain locked until decrypted using the decryptor and the key. Fortunately, there is a free decryptor that can decrypt .aabn files. Below we provide instructions on where to download and how to use a free Aabn File Decrypt Tool.

To decrypt .aabn files, use Aabn File Decrypt Tool

• Download Aabn 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.

Aabn File Decrypt Tool is a free software that can decrypt the encrypted files only in some cases, when the files were encrypted with an ‘offline key’. If the files were encrypted with an ‘online key’, then they cannot be decrypted. The reason for this is that the decryption key is in the hands of criminals and this key can not be determined. This does not mean that if your files are encrypted with an online key, then their contents are lost forever. Fortunately, there are several ways to recover encrypted files. These methods do not involve the use of decryption and therefore can be used in any case, no matter what key the ransomware used to encrypt files.

How to find out which key was used to encrypt files

Since Aabn File Decrypt Tool only decrypts files encrypted with an offline key, each Aabn’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 ‘0565’ – 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’, Aabn 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.

Aabn File Decrypt Tool : “No key for New Variant online ID”

If, when you try to decrypt .aabn files, Aabn 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 Aabn 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.

Aabn File Decrypt Tool : “No key for New Variant offline ID”

If, during decryption of .aabn files, Aabn 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 .aabn files.

This video step-by-step guide will demonstrate How to use STOP Djvu decryptor to Decrypt encrypted files.

How to restore .aabn files

As we mentioned above, in addition to using the Aabn File Decrypt 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 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 the Aabn ransomware virus is completely removed. To scan your computer for ransomware, use free malware removal tools.

Restore .aabn files using Shadow Explorer

The Microsoft Windows has a feature called ‘Shadow Volume Copies’ that can help you to recover .aabn 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 directly to your Windows Desktop.

Once the downloading process is done, extract the saved file to a folder on your device. This will create the necessary files like below.

Start the ShadowExplorerPortable application. Now select the date (2) that you wish to restore from and the drive (1) you wish to recover files (folders) from as shown in the figure below.

On right panel navigate to the file (folder) you wish to restore. Right-click to the file or folder and click the Export button as shown on the image below.

And finally, specify a folder (your Desktop) to save the shadow copy of encrypted file and click ‘OK’ button.

This video step-by-step guide will demonstrate How to recover encrypted files using Shadow Explorer.

Restore .aabn 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 by clicking on the following link.

After the downloading process is done, 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 below.

Double click on qphotorec_win to run PhotoRec for MS Windows. It’ll open a screen as shown on the screen below.

Select a drive to recover as shown on the image below.

You will see a list of available partitions. Select a partition that holds encrypted photos, documents and music as shown on the image below.

Press File Formats button and choose file types to restore. You can to enable or disable the recovery of certain file types. When this is done, click OK button.

Next, press Browse button to select where recovered 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 recovered files is updated in real time. All restored documents, photos and music are written in a folder that you have chosen on the previous step. You can to access the files even if the restore process is not finished.

When the recovery is finished, click on Quit button. Next, open the directory where recovered files are stored. You will see a contents like below.

All recovered personal 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 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 personal computer from Aabn ransomware

Most antivirus applications already have built-in protection system against the crypto virus. Therefore, if your PC system does not have an antivirus application, make sure you install it. As an extra protection, run the HitmanPro.Alert. All-in-all, HitmanPro.Alert is a fantastic tool to protect your personal 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 MS Windows operating system from MS Windows XP to Windows 10.

HitmanPro.Alert can be downloaded from the following link. Save it to your Desktop.

After downloading is done, open the directory in which you saved it. You will see an icon like below.

Double click the HitmanPro Alert desktop icon. When the tool is started, you’ll be displayed a window where you can select a level of protection, like below.

Now click the Install button to activate the protection.

To sum up

This guide was created to help all victims of Aabn ransomware virus. We tried to give answers to the following questions: how to remove ransomware; how to decrypt .aabn files; how to recover encrypted files; 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 Aabn related issues, go to here.