What is Aayu virus?
Aayu virus is a malicious program that encrypts files stored on a computer in order to extort money. This malware is categorized as a data locker ransomware that belongs to the STOP (Djvu) family.
Aayu encrypts files, renames them by appending the .aayu extension, and creates files named “_readme.txt” containing the ransom demand message. For example, a file named “image.jpg” will be renamed to “image.jpg.aayu”, a “document.docx” file to “document.docx.aayu”, “invoice.pdf” to “invoice.pdf.aayu”, and so on.
QUICK LINKS
- What is Aayu virus?
- Remove Aayu virus (ransomware)
- Decrypt .aayu files
- Restore .aayu files
- Video Guide
Aayu ransomware in detail
Aayu is a ransomware that has been observed since 2019. It targets users running Microsoft Windows. In most cases, Aayu requires user actions in order to be installed on the computer. Typically, criminals use various tricks, for example, disguising this malicious program as a freeware, hacked software, a Windows/Office activator or key generator, so that victims download and run Aayu virus on their computer.
Upon infecting a computer, the Aayu ransomware performs the following steps as part of its preparation for encrypting files: creates a folder in the Windows system directory and copies itself to it; adds itself to the list of programs that start up every time the computer is turned on; collects information about the victim’s computer; establishes connection with its command server (C&C).
If Aayu was able to establish a connection with the C&C server, then it sends some information about the victim’s computer to the server, and the server returns a key to it that must be used to encrypt files. Such a key is called ‘online key’ and it is unique for each case of ransomware infection. If a connection to the C&C server has not been established, the ransomware uses a fixed key (so called ‘offline key’), which is unique for each version of STOP (djvu) ransomware, but the same for each case of Aayu infection.
After determining which key to use, Aayu ransomware moves on to the file encryption process. Of course, it does not encrypt absolutely all files, as encrypting Windows system files will cause the computer to stop working. Therefore, the ransomware does not encrypt files located in the system directory of Windows, as well as files with the following extensions: ‘.sys, .dll, .lnk, .ini, .bat’. In addition, Aayu virus does not encrypt files named ‘_readme.txt’. All other files will become the target of the malware, for example, the following file types can be encrypted:
.webp, .7z, .kdc, .dcr, .yml, .dng, .accdb, .dazip, .svg, .css, .xdl, .t12, .rb, .mddata, .qdf, .bc6, .iwd, .rar, .tor, .pdd, .zdc, .z, .sis, .p7c, .cr2, .xlk, .xpm, .dbf, .m3u, .fsh, .wma, .wm, .zip, .vfs0, .iwi, .kf, .zdb, .wmv, .wps, .doc, .wma, .w3x, .wire, .crw, .rim, .wcf, .xbdoc, .big, .ods, .zif, .mef, .ntl, .pptx, .xmmap, .vtf, .xwp, .mpqge, .xar, .wot, .dba, .wbd, .zip, .sie, .pem, .m2, .wpb, .y, .xml, .wp6, .p7b, .litemod, .apk, .x3d, .der, .layout, .arch00, .odm, .cfr, .wbm, .odp, .jpg, .vdf, .nrw, .rofl, .wpd, .xyp, .bc7, .docm, .sum, .wmd, .slm, .xlsb, .ncf, .cas, .zi, .csv, .wmo, .wbk, .eps, .wsc, .wpt, .hvpl, .lrf, .p12, .srf, .vpp_pc, .db0, .xll, .bkf, .xx, .erf, .rw2, .wpe, .odb, .syncdb, .ltx, .ws, .gdb, .ysp, .itm, .ztmp, .dwg, .mov, .wpw, .asset, .bik, .ai, .pst, .wmf, .wp5, .snx, .3ds, .wp, .icxs, .desc, .mdf, .xy3, .mlx, .0, .raf, .psk, .pptm, .mrwref, .xmind, .itdb, .wn, .vpk, .py, .wpa, .js, .1st, wallet, .crt, .rtf, .wav, .1, .x3f, .cer, .wsh, .docx, .t13, .lvl, .wri, .orf, .xls, .wbz, .sav, .xyw, .re4, .qic, .zw, .wbmp, .mdb, .psd, .jpe, .z3d, .wpd, .cdr, .m4a, .xxx, .xbplate, .sidd, .blob, .kdb, .wdb, .wdp, .dxg, .vcf, .ptx, .flv, .bar, .hkx, .3fr, .pak, .wgz, .forge, .pef, .2bp, .bay, .ff, .bsa, .hkdb, .ppt, .yal, .xlgc, .xf, .srw, .sql, .indd, .wp4, .ibank, .xlsx, .map, .pfx, .dmp, .xlsx, .esm, .xls, .itl, .r3d, .odc, .3dm, .fpk, .menu, .ybk, .fos, .rgss3a, .wps, .rwl, .wotreplay, .wbc, .webdoc, .mp4, .raw, .sid, .epk, .das, .sidn, .pdf, .x3f, .wb2, .xlsm, .gho, .x, .zabw, .xdb, .mcmeta, .jpeg, .hplg, .sr2, .txt, .wp7
All encrypted files become completely useless, their contents cannot be read in any way. To clearly show that the files are encrypted, the ransomware virus appends a new ‘.aayu’ extension at the end of the filename of each encrypted file. This means the following: if the file had the name ‘photo-image.jpg’, then after it has been encrypted, it will be called ‘photo-image.jpg.aayu’. In all directories where there are encrypted files, Aayu virus drops a file named ‘_readme.txt’
This file contains text written by Aayu authors. In this message, the criminals report that the user’s files were encrypted and the only way to get them back is to purchase a key and a decryptor. Attackers give the victim 72 hours. At this time, the key will cost $490, after 72 hours the ransom will increase to $980. The message also contains the contact information of the criminals, using which the victim can check the ability of the attackers to decrypt .aayu files, as well as find out where to send the ransom.
Text presented in the _readme.txt file:
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.chReserve e-mail address to contact us:
datarestorehelp@airmail.ccYour personal ID:
0563xxxxxxxx
In file ‘_readme.txt’, criminals scare victims by saying that encrypted files cannot be decrypted without paying a ransom. And unfortunately this is true, the contents of the files cannot be read while the files are encrypted, and a key and decryptor are needed to decrypt them. Fortunately, there is a free Aayu File Decrypt Tool. This decryptor can help each victim to decrypt .aayu files for free. But in addition to the decryptor, the key is still necessary. As we reported above, the virus can use two types of keys. An offline key can be determined by researchers, but only criminals have an online key. Thus, files encrypted with so called ‘offline key’ can be decrypted. And all files that have been encrypted with so called ‘online key’ cannot yet be decrypted. In this case, the alternative methods listed below in this article can be used to recover the contents of these files.
Threat Summary
| Name | Aayu ransomware, Aayu file virus |
| Type | File locker, Ransomware, Crypto malware, Crypto virus, Filecoder |
| File extension | .aayu |
| Ransom note | _readme.txt |
| Contact | support@bestyourmail.ch, datarestorehelp@airmail.cc |
| Ransom amount | $980 or $490 in Bitcoins |
| Detection Names | DropperX-gen [Drp], Gen:Heur.Mint.Zard.52, W32/Kryptik.HQVE!tr, UDS:DangerousObject.Multi.Generic, ML/PE-A, Trojan.MalPack.GS, Trojan.Win32.Crypt, Trojan.Win32.Save.a, Ransom.Stop.P5Malicious.high.ml.score |
| Symptoms | Cannot open files stored on the computer. Your files now have a different extension. Files called such as ”, ‘#_README_#’, ‘_DECRYPT_’ or ‘recover’ in each folder with at least one encrypted file.. Your desktop is locked with a message about How to pay to unlock your system. |
| Distribution ways | Phishing email scam that attempts to scare users into acting impulsively. Drive-by downloads from a compromised web-site. Social media, such as web-based instant messaging applications. Malicious web sites. |
| Removal | Aayu ransomware removal guide |
| Decryption | Aayu File Decrypt Tool |
How to remove Aayu virus (ransomware)
Before you start decrypting or recovering .aayu files, you need to remove the Aayu virus. 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 read the entire instruction manual carefully and make sure to understand it all. We advise you not to skip any steps, each of the steps is very important and must be completed by you. In order not to get confused and not miss an important point in the instructions, we recommend that you print this article or open it on your smartphone.
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 Aayu 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 Aayu virus, then let us know in the comments, we will try to help you.
To remove Aayu virus, follow the steps below:
Kill Aayu virus
Press CTRL, ALT, DEL keys together.
Click Task Manager. Select the “Processes” tab, look for something suspicious that is the Aayu 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 Aayu 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 Aayu 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 Aayu 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 Aayu 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 Aayu virus
Run Task Manager and select the “Start-Up” tab. Right click to the Aayu startup entry and select Open File Location as shown below.
A directory containing one file will open in front of you, this file is the Aayu 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 Aayu 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 Aayu 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.
326379 downloads
Author: Malwarebytes
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 Aayu 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 Aayu 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 Aayu ransomware virus, we recommend using Kaspersky virus removal tool (KVRT). It is a free removal utility that can check your PC for a wide range of security threats such as ransomware, adware, spyware, potentially unwanted software, trojans, worms as well as other malicious software. It will perform a deep scan of the system including hard drives and Windows registry. When a malicious software is found, it will help you to delete all detected threats from your computer by a simple click.
Download Kaspersky virus removal tool on your PC from the following link.
129054 downloads
Author: Kaspersky® lab
Category: Security tools
Update: March 5, 2018
When downloading is done, double-click on the Kaspersky virus removal tool icon. Once initialization process is complete, you will see the Kaspersky virus removal tool screen as shown on the image below.
Click Change Parameters and set a check near all your drives. Press OK to close the Parameters window. Next press Start scan button to perform a system scan for the Aayu virus and other trojans and harmful software. This procedure can take some time, so please be patient. While the utility is scanning, you can see how many objects and files has already scanned.
When the checking is finished, KVRT will show a list of found items such as the one below.
Review the report and then click on Continue to begin a cleaning procedure.
How to decrypt .aayu files
Files with the extension ‘.aayu’ are encrypted files. The virus uses a long key and a strong encryption algorithm, so it is impossible to decrypt files without a key and decryptor. Criminals demand a ransom for the key and the decryptor. Of course, even paying a ransom, there is no guarantee that victims will receive the required key and decryptor. Fortunately, there is a free Aayu File Decrypt Tool that allows everyone to decrypt .aayu files for free.
Aayu File Decrypt tool (STOP Djvu decryptor)
To decrypt .aayu files, use Aayu File Decrypt tool:
- Go to the following link to download Aayu File Decrypt tool.
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.
Aayu 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
Below we show two ways to help you determine what type of key was used to encrypt your files. This is very important, since the type of key determines whether it is possible to decrypt .aayu files. We recommend using the second method, as it is more accurate.
Personal ID is highlighted here
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 – 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 Aayu ransomware 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’, Aayu ransomware 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.
Aayu File Decrypt Tool : “No key for New Variant online ID”
If, when you try to decrypt .aayu files, Aayu 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 Aayu 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.
Aayu File Decrypt Tool : “No key for New Variant offline ID”
If, during decryption of .aayu files, Aayu 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 .aayu files.
This video step-by-step guide will demonstrate How to use STOP Djvu decryptor to Decrypt encrypted files.
How to restore .aayu files
If the Aayu File Decrypt tool cannot decrypt the encrypted files or your data is encrypted with an online key, then there is no need to despair. Fortunately, there are several alternative methods that can allow everyone to recover the contents of encrypted files. Each of these methods does not involve the use of special knowledge and paid programs and can be performed by everyone. We have prepared an instruction with illustrations, which describes in detail the process of data recovery. Before you begin data recovery, if you have not completed step 1, then go back. You must be 100% sure that Aayu ransomware virus is completely removed. We recommend using free malware removal tools.
Use ShadowExplorer to recover .aayu files
The first and very simple way to restore encrypted files to the state in which they were before encryption is to restore files from their Shadow Copies. The Shadow Volume Copies are copies of files and folders that Windows automatically saved as part of system protection. This feature is fantastic at rescuing personal files that were locked by Aayu ransomware. The guide below will give you all the details.
Visit the following page to download ShadowExplorer. Save it on your Windows desktop or in any other place.
438652 downloads
Author: ShadowExplorer.com
Category: Security tools
Update: September 15, 2019
Once the downloading process 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 shown on the screen below.
Double click ShadowExplorerPortable to run it. You will see the a window as shown in the figure below.
In top left corner, select a Drive where encrypted personal files are stored and a latest restore point as shown in the following example (1 – drive, 2 – restore point).
On right panel look for a file that you wish to recover, right click to it and select Export as displayed below.
This video step-by-step guide will demonstrate How to recover encrypted files using Shadow Explorer.
Restore .aayu files with PhotoRec
Another way to recover encrypted files is to use data recovery programs. There are many such programs, but most of them are paid. We recommend using a program called PhotoRec. It has all the necessary functions and is completely free.
Download PhotoRec by clicking on the following link. Save it directly to your Microsoft Windows Desktop.
When the download 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 as displayed on the image below.
Double click on qphotorec_win to run PhotoRec for Windows. It will show a screen as shown in the following example.
Choose a drive to recover as shown on the screen below.
You will see a list of available partitions. Choose a partition that holds encrypted personal files as displayed on the image below.
Click File Formats button and select file types to restore. You can to enable or disable the recovery of certain file types. When this is complete, click OK button.
Next, press Browse button to choose where restored personal files should be written, then press Search. We strongly recommend that you save the recovered files to an external drive.
Count of restored files is updated in real time. All restored personal files are written in a folder that you have chosen on the previous step. You can to access the files even if the recovery process is not finished.
When the restore is finished, click on Quit button. Next, open the directory where restored documents, photos and music are stored. You will see a contents as shown in the figure below.
All restored photos, documents and music are written in recup_dir.1, recup_dir.2 … sub-directories. If you’re looking 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 Aayu ransomware
Most antivirus apps already have built-in protection system against the crypto virus. Therefore, if your machine does not have an antivirus program, 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 HitmanPro.Alert. Save it to your Desktop so that you can access the file easily.
When the downloading process is finished, open the file location. You will see an icon like below.
Double click the HitmanPro Alert desktop icon. When the utility is opened, you will be shown a window where you can select a level of protection, as displayed in the figure below.
Now press the Install button to activate the protection.
Finish words
This article was created to help all victims of the Aayu ransomware virus. We tried to give answers to the following questions: how to remove ransomware; how to decrypt .aayu 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 article has helped you.
If you have questions, then write to us, leaving a comment below. If you need more help with Aayu ransomware related issues, go to here.
My files are encrypted with this aayu virus and the key is online. I’ve tried the STOP Djvu decryptor but that didn’t work. Is there any way I can save my data or should I just give up and completely reinstall Windows?
Try to recover files using PhotoRec and ShadowExplorer, but you need to be sure that the virus is removed!