Remove AAYU Ransomware Virus (DECRYPT .aayu FILES)

remove AAYU ransomware virus and learn how to decrypt or repair files with .aayu extension (free guide)

AAYU ransomware virus & why you should avoid It

Contents

AAYU ransomware virus & why you should avoid It
Proactive steps you can take to protect your company against this virus
Remove AAYU ransomware virus and recover your data
Decrypt AAYU files
Frequently Asked Questions

AAYU ransomware is a malicious computer virus that cybercriminals are already spreading through their usual routes, including online torrent platforms, emails, and attachments. It is a confirmed variant of STOP/DJVU ransomware family. In cases whereby this virus manages to infect a computer system, it begins encryption of files contained in it. Afterward, it will append .aayu extension to all the files as a means of identification. E.g. files that had names like 1.jpg or 2png prior to the malware infection will now become 1.jpg.aayu or 2.png.aayu as the case may be.

This virus is part of STOP/DJVU ransomware series. Similarly, the target of criminals behind it remains unchanged (i.e., unsuspecting computer owners) using the old three-pronged method whereby they infect computers, encrypt files contained in them, and demand for ransom while promising to provide decryption tools.

They would clone software contents that are in high demand, embed them with malware and upload to online torrent platforms for potential victims to download. Another method used by them is to create emails and attachments, embed them with malware and forward to as many random addresses as possible. Due to these risk factors, it has become expedient for the computer user to always take precautionary measures to avoid becoming a victim.

The ransomware drops a money-demanding text note

During the cyberattack, the virus drops text notes called as _readme.txt. It informs the victim about what has occurred and why it is important for ransom to be paid to enable the victim to receive decryption tools that reverse the encryption. They state that it’s the only way for the victim to recover the encrypted files; otherwise, the victim will lose them forever. In anticipation of the victim’s possible SOS message, they leave two email addresses, namely support@bestyourmail.ch and datarestorehelp@airmail.cc.

Victims that take the bait to communicate with them will be informed that the ransom fee is $980, but victims willing to pay within 3 days of being notified would be entitled to 50% ransom fee slash. Therefore, they would now be expected to pay $490 but once the deadline is exceeded, they would insist on the maximum fee.

To further complicate issues for the victim, the cybercriminals notify that payment can only be transferred via cryptocurrency. This payment method is convenient for them because it ensures the criminals won’t reveal their real identity.

However, victims of ransomware attacks are warned never to comply with the demands of cybercriminals, no matter the pressure. Global security organizations such as the FBI also support this stance, and some of the reasons they gave are provided below:

It is illegal to pay ransom in any guise, based on existing laws.
Ransom payment offers no benefit to the victim because cybercriminals don’t keep to their promise of providing the decryption key, thereby causing more grief to the victim.
Paying ransom encourages criminality as it gives them an incentive to continue their criminal acts.
It also enables cybercriminals to expand their illegal operations and victimize others.
Victims that pay ransom make themselves vulnerable to future attacks and extortions.

Take action to protect your PC now

Also, it should be noted that encryption and ransom demand is not the only dangers associated with AAYU ransomware virus because they’re known to trigger the release of RATs. RAT is an acronym that means Remote Access Trojans. They expose the victim and enable cybercriminals to obtain sensitive personal information that may include banking details, browsing history, cryptocurrency wallets, software login credentials etc. Such a situation could lead to further attacks in other forms.

Due to these factors, victims of the described malware must remove AAYU ransomware virus as quickly as possible to limit its possible damages. This can be done by setting up the infected computer using the option of Safe Mode with Networking. It would open up the system while limiting other functions that might stand in the way. A good tool to try is RESTORO (secure download link), which is excellent for repairing virus damage on Windows OS files.

Ransomware Summary

Name	AAYU Ransomware Virus
Type	Ransomware; Crypto-malware; Virtual Extortion Virus
Family	STOP/DJVU
Encryption type	RSA 2048 + Salsa20
Previous versions	OOPU, MMPU, MMVB, MMDT, EEWT, EEMV, (find full list here)
Version	563rd
Extension	.aayu
Cybercriminal emails	support@bestyourmail.ch, datarestorehelp@airmail.cc
Additional malware dropped	Azorult or Vidar Trojan
Damage	The ransomware uses encryption to maliciously modify all files on the PC and marks their original names with .aayu extension. Ransom notes called as _readme.txt will be dropped in every computer folder. This piece of malware usually drags VIDAR Stealer alongside it and also eliminates VSS from the system. On top of that, it tends to modify Windows HOSTS file to restrict computer user’s access to cybersecurity-related websites online.
Ransom note	_readme.txt
Ransom demand	$490-$980 in Bitcoin
Distribution	Victims often download this ransomware along illegal torrent downloads, cracked software, activators, key generators or tools like KMSPico.
Known software cracks to contain this malware	Corel Draw, Tenorshare 4ukey, Adobe Photoshop, Cubase, Adobe Illustrator, Internet Download Manager, Tally, League of Legends.
Detection names	Trojan:Win32/Krypter.AA!MTB (Microsoft), Gen:Variant.Jaik.94865 (B) (Emsisoft), UDS:DangerousObject.Multi.Generic (Kaspersky), Gen:Variant.Jaik.94865 (BitDefender), Trojan.MalPack.GS (Malwarebytes), ML.Attribute.HighConfidence (Symantec) see all detection name variations on VirusTotal
Removal	Remove ransomware and related malware from your PC using trustworthy software. To repair virus damage on Windows OS files, consider scanning with RESTORO (secure download link).

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Proactive steps you can take to protect your company against this virus

Computers should be used responsibly; otherwise, they could become infected with AAYU ransomware virus or other malware variants. Computer users should avoid risky activities like visiting online torrent platforms, opening emails without first scrutinizing them, sharing software contents via P2P platforms etc.

Cybercriminals are constantly seeking for loopholes to exploit in their attempts to spread malware. This could be in the form of cloning popular software contents and embedding them with malware, sending spam emails with attachments that contain viruses etc. Therefore, computer users should not open emails they’re not sure of their source and neither should they visit online torrent platforms when they’re in need of software.

Cybercriminals can be very desperate and they often go the extra mile in using deceptive means to achieve their inordinate objectives. However, users can secure their computer by doing the right things like legally getting their software needs (from the original software producers/affiliates), checking properly before opening emails, and having genuine antivirus software installed on their PC. Some software users don’t like paying the fees requested by the producers and in trying to cut corners, they end up downloading cloned versions that are embedded with malware.

Below is a list of some of the software contents most commonly pirated and used by cybercriminals in spreading malware:

Cubase;
Adobe Photoshop;
Corel Draw;
Adobe Illustrator;
Fifa 20;
VMware Workstation;
Internet Download Manager;
League of Legends;
Tenorshare 4ukey;
AutoCad;
Adobe Premiere Pro.

Aside the risks involved in such unwholesome acts, it should also be noted that it’s unfair to exploit other people’s products without paying for it. The brand owners must have spent a lot of resources both during research and development, and thus they deserve to earn returns on their investments. In addition, the fees they request is little compared to the vast amounts of money cybercriminals demand from their victims. Even when victims pay the huge fees, they would unlikely get the decryption tools needed to restore their encrypted files. Other inconveniences the victims would suffer include loss of valuable time, loss of essential files and accompanying distress etc.

Cybercriminals also exploit popular files such as PDF, DOCX and XLS because they enable macro functions that make it easy for malware to be embedded in an attachment and distributed. However, victims of AAYU ransomware virus are warned to desist from visiting websites that claim to have decryption tools because they’re mostly ineffective. So far, only Emsisoft and DiskTuna have been effective to an extent.

Remove AAYU ransomware virus and recover your data

As stated earlier, it is vital to remove AAYU ransomware virus as quickly as possible so that remedial measures can be taken. This should be done by login into the computer via Safe Mode with Networking while simultaneously installing and running good antivirus software. The next step that we recommend taking is running RESTORO (secure download link) and scanning your PC to detect and repair virus-damaged Windows OS files. After securing the computer, other important steps that should be taken are listed below:

Change all passwords used in the computer prior to the ransomware attack.
Make use of backup to restore lost files.
If the above option is unavailable, you may consider searching for confirmed data recovery solutions.
Report to relevant local authorities.

OUR GEEKS RECOMMEND

Our team recommends removing malware using a professional antivirus software and then using the following tool to repair virus damage to Windows system files:

REPAIR VIRUS DAMAGE TO YOUR COMPUTER

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RESTORO uses AVIRA scanning engine to detect existing spyware and malware. If any are found, the software will eliminate them.

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GeeksAdvice.com editors select recommended products based on their effectiveness. We may earn a commission from affiliate links, at no additional cost to you. Learn more.

AAYU Ransomware Virus Removal Guidelines

Method 1. Enter Safe Mode with Networking

Step 1. Start Windows in Safe Mode with Networking

Before you try to remove AAYU Ransomware Virus virus, you must start your computer in Safe Mode with Networking. Below, we provide the easiest ways to boot PC in the said mode, but you can find additional ones in this in-depth tutorial on our website – How to Start Windows in Safe Mode. Also, if you prefer a video version of the tutorial, check our guide How to Start Windows in Safe Mode on Youtube.

Instructions for Windows XP/Vista/7 users

First of all, turn off your PC. Then press the Power button to start it again and instantly start pressing F8 button on your keyboard repeatedly in 1-second intervals. This launches the Advanced Boot Options menu.
Use arrow keys on the keyboard to navigate down to Safe Mode with Networking option and press Enter.

Instructions for Windows 8/8.1/10/11 users

Open Windows Start menu, then press down the Power button. On your keyboard, press down and hold the Shift key, and then select Restart option.
This will take you to Windows Troubleshoot screen. Choose Troubleshoot > Advanced Options > Startup Settings > Restart. Tip: If you can't find Startup Settings, click See more recovery options.
In Startup Settings, press the right key between F1-F9 to enter Safe Mode with Networking. In this case, it is the F5 key.

Step 2. Remove files associated with the virus

Now, you can search for and remove AAYU Ransomware Virus files. It is very hard to identify files and registry keys that belong to the ransomware virus, Besides, malware creators tend to rename and change them repeatedly. Therefore, the easiest way to uninstall such type of a computer virus is to use a reliable security program such as INTEGO Antivirus, which also includes data recovery software. For virus damage repair, consider using RESTORO.

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Method 2. Use System Restore

In order to use System Restore, you must have a system restore point, created either manually or automatically.

Step 1. Boot Windows in Safe Mode with Command Prompt

Instructions for Windows XP/Vista/7 users

Shut down your PC. Start it again by pressing the Power button and instantly start pressing F8 button on your keyboard repeatedly in 1-second intervals. You will see Advanced Boot Options menu.
Using arrow keys on the keyboard, navigate down to Safe Mode with Command Prompt option and press Enter.

Instructions for Windows 8/8.1/10/11 users

Launch Windows Start menu, then click the Power button. On your keyboard, press down and hold the Shift key, and then choose Restart option with the mouse cursor.
This will take you to Windows Troubleshoot screen. Choose Troubleshoot > Advanced Options > Startup Settings > Restart. Tip: If you can't find Startup Settings, click See more recovery options.
In Startup Settings, press the right key between F1-F9 to enter Safe Mode with Command Prompt. In this case, press F6 key.

Step 2. Start System Restore process

Wait until system loads and command prompt shows up.
Type cd restore and press Enter, then type rstrui.exe and press Enter. Or you can just type %systemroot%system32restorerstrui.exe in command prompt and hit Enter.
This launches System Restore window. Click Next and then choose a System Restore point created in the past. Choose one that was created before ransomware infection.
Click Yes to begin the system restoration process.

After restoring the system, we recommend scanning the system with antivirus or anti-malware software. In most cases, there won't be any malware remains, but it never hurts to double-check. In addition, we highly recommend checking ransomware prevention guidelines provided by our experts in order to protect your PC against similar viruses in the future.

Alternative software recommendations

Malwarebytes Anti-Malware

Removing spyware and malware is one step towards cybersecurity. To protect yourself against ever-evolving threats, we strongly recommend purchasing a Premium version of Malwarebytes Anti-Malware, which provides security based on artificial intelligence and machine learning. Includes ransomware protection. See pricing options and protect yourself now.

System Mechanic Ultimate Defense

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Disclaimer. This site includes affiliate links. We may earn a small commission by recommending certain products, at no additional cost for you. We only choose quality software and services to recommend.

Decrypt AAYU files

Fix and open large AAYU files easily:

It is reported that STOP/DJVU ransomware versions encrypt only the beginning 150 KB of each file to ensure that the virus manages to affect all files on the system. In some cases, the malicious program might skip some files at all. That said, we recommend testing this method on several big (>1GB) files first.

Create a copy of encrypted file to a separate folder using Copy > Paste commands.
Now, right-click the created copy and choose Rename. Select the AAYU extension and delete it. Press Enter to save changes.
In the prompt asking whether you want to make the changes as file might become unusable, click OK.
Try opening the file.

STOP/DJVU decryption tool usage guide

STOP/DJVU ransomware versions are grouped into old and new variants. AAYU Ransomware Virus is considered the new STOP/DJVU variant, just like OOPU, MMPU, MMVB, MMDT, EEWT, EEMV, (find full list here). This means full data decryption is now possible only if you have been affected by offline encryption key. To decrypt your files, you will have to download Emsisoft Decryptor for STOP DJVU, a tool created and maintained by a genius security researcher Michael Gillespie.

Note! Please do not spam the security researcher with questions whether he can recover your files encrypted with online key - it is not possible.

In order to test the tool and see if it can decrypt AAYU files, follow the given tutorial.

Download the decryption tool from Emsisoft.
Click the little arrow next to your download and choose Show in Folder.
Now, right-click the file and choose Run as Administrator. If asked, enter administrator's password.
In UAC window, click Yes.
Click Yes to agree to software terms in both windows.
The tool will automatically include C:// disk as a location to decrypt. The file recovery tool will prepopulate the locations to scan, including connected data storage drives or network drives. Click Add folder if you wish to add additional locations.
In Options tab, you can choose to keep encrypted file copies. We recommend leaving this option selected, especially if you do not know if the decryption tool will work.
Click Decrypt to start restoring AAYU files. You will see the progress in the Results tab. Here, you can see messages from the tool, such as whether the decryption procedure is successful, or you need to wait for an update.
You might also be informed that online key was used to encrypt your files. In such case, the decryption tool won't work for you, and the only way to recover your files is to use a data backup.

Meanings of decryptor's messages

The AAYU decryption tool might display several different messages after failed attempt to restore your files. You might receive one of the following messages:

Error: Unable to decrypt file with ID: [example ID]

This message typically means that there is no corresponding decryption key in the decryptor's database.

No key for New Variant online ID: [example ID]
Notice: this ID appears to be an online ID, decryption is impossible

This message informs that your files were encrypted with online key, meaning no one else has the same encryption/decryption key pair, therefore data recovery without paying the criminals is impossible.

Result: No key for new variant offline ID: [example ID]
This ID appears to be an offline ID. Decryption may be possible in the future.

If you were informed that an offline key was used, but files could not be restored, it means that the offline decryption key isn't available yet. However, receiving this message is extremely good news, meaning that it might be possible to restore your AAYU extension files in the future. It can take a few months until the decryption key gets found and uploaded to the decryptor. We recommend you to follow updates regarding the decryptable DJVU versions here. We strongly recommend backing up your encrypted data and waiting.

Report Internet crime to legal departments

Victims of AAYU Ransomware Virus should report the Internet crime incident to the official government fraud and scam website according to their country:

In the United States, go to the On Guard Online website.
In Australia, go to the SCAMwatch website.
In Germany, go to the Bundesamt für Sicherheit in der Informationstechnik website.
In Ireland, go to the An Garda Síochána website.
In New Zealand, go to the Consumer Affairs Scams website.
In the United Kingdom, go to the Action Fraud website.
In Canada, go to the Canadian Anti-Fraud Centre.
In India, go to Indian National Cybercrime Reporting Portal.
In France, go to the Agence nationale de la sécurité des systèmes d’information.

If you can't find an authority corresponding to your location on this list, we recommend using any search engine to look up "[your country name] report cyber crime". This should lead you to the right authority website. We also recommend staying away from third-party crime report services that are often paid. It costs nothing to report Internet crime to official authorities.

Another recommendation is to contact your country's or region’s federal police or communications authority.

Frequently Asked Questions

✓ How can I open .AAYU files?

You can only open AAYU files if you have the decryption key, or if you were affected by offline encryption type.

✓ How do I know if my files were encrypted with offline or online encryption?

To figure out whether you were affected by offline encryption, please go to C:/SystemID/PersonalID.txt and see if the string inside of it ends in t1. You can also try using Emsisoft Decryptor for STOP/DJVU.

✓ My files contain very important information (family memories). Every tool I used says it is impossible to decrypt. What should I do?

Please follow the guidances provided by the official AAYU decryption tools and believe what they say. If they say it is impossible to decrypt, it really is so. There is no magic tool or human capable of decrypting your files hiding somewhere. Encryption is a technique created to be nearly impossible to decrypt without a special private key (held by the criminals).

✓ I am afraid virus is still in my computer system. What should I do?

We advise scanning with anti-virus, anti-malware, malware removal tools or software like RESTORO to eliminate virus damage on the system. If you do not trust using a single tool, try running one after another. However, we do not recommend keeping several security programs on a computer at once as they can interfere with each other's work.

✓ I saw several Youtube videos suggesting secret decryption tools. Can I trust them?

Beware of fake AAYU decryption tools circulating around the web. Cyber criminals are uploading them to various shady websites, also might be promoting them via suspicious Youtube videos. These programs can infect your computer even more heavily (Trojans, miners, etc.). We suggest being extremely cautious around the web. If there will be an official STOP/DJVU decryption tool available, it will be widely discussed in public media.

Norbert Webb

Norbert Webb is the head of Geek’s Advice team. He is the chief editor of the website who controls the quality of content published. The man also loves reading cybersecurity news, testing new software and sharing his insights on them. Norbert says that following his passion for information technology was one of the best decisions he has ever made. “I don’t feel like working while I’m doing something I love.” However, the geek has other interests, such as snowboarding and traveling.