Geek's Advice

AEUR ransomware used as a virtual extortion tool that keeps victim’s files hostage

AEUR ransomware is a malicious computer virus that uses RSA Salsa20 encryption to lock victim’s files on the compromised computer. This infection originates from STOP/DJVU ransomware family which already has over 300 variants. Once launched on the computer, the virus encrypts all files and marks them with .aeur extensions, drops _readme.txt notes in every folder, and deletes Volume Shadow Copies from the system. To illustrate, a file originally called 1.jpg becomes 1.jpg.aeur after the encryption and becomes impossible to open no matter what program the victim attempts to use. As stated in the ransom note, the virus developers can decrypt .aeur files for a large amount of money – $490 if paid within 3 days or $980 later. This ransom amount must be transferred to attackers in Bitcoin. To get further details from cybercriminals, the victim can write them via two emails provided in the _readme.txt file – manager@mailtemp.ch or managerhelper@airmail.cc.

AEUR ransomware purpose is to make one’s files inaccessible using encryption algorithms which are typically used to secure military-grade secrets. The virus locks the very first 150 KB of data in each file, which corrupts the file quickly then jumps onto next file in the queue. This method, however, allows repairing certain file formats with some data loss at the beginning of the file (examples include audio or video files). You can find a more detailed tutorial on repairing these files in this guide.

AEUR decryption tool requires unique private key to function, and criminals provide the pricing of both in the _readme.txt note. They state that if the victim writes to them within 72 hours, the price will be $490. If the victim writes and pays later, the price will be $980. The virus’ developers know about the infection timestamp because the virus saves it on the victim’s computer and also sends this information to their Command&Control server. The attackers won’t accept Euros or Dollars – they will ask to purchase Bitcoins equivalent the amount and transfer it to the criminals’ wallet. This transaction type helps to keep them anonymous. To convince the victim pay sooner, they also recommend sending one small encrypted file to test the decryption tool first, promising to respond with a clean file version.

Our team experts, as well as other reputable cybersecurity-related sources and FBI DO NOT RECOMMEND paying the ransom due to the following reasons:

• Paying the criminals can do nothing as there are no assurance that the attackers will provide you with decryption tools after receiving your money.
• In some countries, transferring ransom payment is considered illegal.
• Ransomware operators collect incredible amounts of money each year – their income is calculated in millions. This attracts other people to join and consequently leads to more and more disastrous cyber attacks each year. Please, do not contribute to the growth of this by paying the ransom!
• STOP/DJVU variants like AEUR virus install information-stealer dubbed AZORULT. The information collected by this Trojan can be used to blackmail you further. Don’t waste your money because these sneaky crooks will try to rip you off financially as much as possible!

REMOVE MALWARE & REPAIR VIRUS DAMAGE

Details about the ransomware damage

AEUR ransomware infection can be recognised quite easily by experienced cybersecurity experts because this virus runs a fake Windows update prompt at the beginning of the attack. However, regular computer users might not notice anything suspicious as this prompt can be easily mistaken for a legitimate operating system update. The crooks use this method to conceal their attack, trying to convince the victim that system slowdown is caused by installation of required system components. At the same time, the whole computer data corruption procedure begins as an executable named by 4 random characters such as B5DH.exe starts to scan computer folders and encrypts files stored in them. The malware then launches Command Prompt to run the following command and delete Volume Shadow Copies from the system:

^{vssadmin.exe Delete Shadows /All /Quiet}

Without Volume Shadow Copies that Windows creates as part of a system restore point, there is no way to recover files using the said System Restore Points. In addition, the virus attempts to isolate the victim from attack-related information online by adding a list of restricted domains to Windows HOSTS file. By mapping these domains to localhost IP, the virus ensures that the victim will run into DNS_PROBE_FINISHED_NXDOMAIN error in web browser instead of opening the website the user tries to reach. You may want to learn how to reset HOSTS file back to default.

After the attack, the ransomware victim might also find other suspicious files on the computer. Some of the dropped files are related to information that helps to identify the victim. For example, one of these files is called bowsakkdestx.txt (you can find victim’s public encryption key and personal ID string in it) and PersonalID.txt (victim’s ID only).

It is important to mention something that ransomware authors didn’t talk about in the ransom note – the ransomware drops information-stealing Trojan called AZORULT. It can be used to remotely access victim’s computer and download, delete, list victim’s files, drop more malware, steal login credentials, browser-saved data (passwords, browsing history), Steam, Telegram login details, cryptocurrency wallets and more.

Needless to say, we strongly recommend you to remove AEUR ransomware virus from your computer as fast as you can. We have prepared a guide for you to follow which you can find down below. First, you will need to use professional antivirus software of your choice (we highly recommend VB100-certified program INTEGO Antivirus) for malware removal. Additionally, we recommend downloading RESTORO to repair virus damage on Windows OS files.

Ransomware Summary

REMOVE MALWARE & REPAIR VIRUS DAMAGE

How ransomware-type viruses are distributed

Viruses that come from STOP/DJVU family, including AEUR ransomware, are generally distributed in a form of software cracks. The criminals disguise malicious code into tools that are typically used to illegally activate paid software licenses. Some victims infected with STOP/DJVU versions reported getting infected after trying to obtain these legitimate programs illegally:

• Adobe Photoshop;
• Corel Draw;
• Cubase;
• Adobe Illustrator;
• Windows activation tools such as KMSPico.

We strongly recommend you to avoid visiting such unconfirmed software download sources and avoid getting software from torrent downloads altogether. By using pirated programs, you not only risk infecting your computer with severe malware, but also infringe copyrights of legitimate software developers and can get fined by your local authorities. Even if it seems that the software installation went smoothly, you can already be infected with Trojan, cryptocurrency miner or another piece of malware that operates silently and doesn’t show any noticeable signs of existence. Besides, it can take months until you notice presence of such programs, and the damage will be enormous.

Ransomware, just like other forms of malware are also actively distributed using old yet very popular technique – malicious email spam. Cybercriminals tend to inject scripts into various document formats, such as DOCX, XLS, PDF or others and opening such file can activate it. The script then proceeds to download threats from specific domains and open them on your computer. Beware that criminals tend to disguise viruses under legitimate-looking document names, such as invoice, payment information, parcel delivery details, order summaries and similar. Be vigilant and avoid clicking on such email attachments or links included if you can spot one of the following red flags:

• You did not expect to receive the email at all;
• The message tone seems urgent and invites you to review attached contents immediately;
• The sender pretends to be someone from a reputable company, yet the email contains grammar errors and logos seem off;
• Spoofed email address;
• Your email box provider marks the letter as spam.

Lastly, victims of AEUR ransomware should know that ZORAB malware operators hide their virus in fake STOP/DJVU decryption tools online. Opening these will get your files double-encrypted. Remember – if an official decryption tool appears, you will find references to it on all the most reputable cybersecurity news websites and not some suspicious sites.

Remove AEUR ransomware virus and decrypt your files

It is best to remove AEUR ransomware virus without any hesitation – the sooner, the better. This way, you will prevent any further damage to your computer and your privacy. We recommend a two-step rescue plan which should start with usage of a robust security software to eliminate malware from your system. We strongly recommend INTEGO Antivirus to get rid of malware. Next, we suggest scanning with RESTORO to identify computer issues and repair virus damage to Windows OS files.

Following a successful AEUR virus removal, take these post-infection actions:

• Report cybercrime incident to your local authority responsible for handling such cases. You can find some references below the article.
• Use data backups to restore files (if you have them).
• Try instructions to decrypt or repair files affected by STOP/DJVU versions.
• We also recommend changing your passwords, especially for sites that you chose to save login credentials for in your browser.

OUR GEEKS RECOMMEND

Our team recommends a two-step rescue plan to remove ransomware and other remaining malware from your computer, plus repair caused virus damage to the system:

STEP 1. REMOVE AUTOMATICALLY WITH ROBUST ANTIVIRUS

REMOVE & PROTECT WITH INTEGO

Get INTEGO ANTIVIRUS for Windows to remove ransomware, Trojans, adware and other spyware and malware variants and protect your PC and network drives 24/7.. This VB100-certified security software uses state-of-art technology to provide protection against ransomware, Zero-Day attacks and advanced threats, Intego Web Shield blocks dangerous websites, phishing attacks, malicious downloads and installation of potentially unwanted programs.

Use INTEGO Antivirus to remove detected threats from your computer.

Read full review here.

STEP 2. REPAIR VIRUS DAMAGE TO YOUR COMPUTER

DOWNLOAD RESTORO

RESTORO provides a free scan that helps to identify hardware, security and stability issues and presents a comprehensive report which can help you to locate and fix detected issues manually. It is a great PC repair software to use after you remove malware with professional antivirus. The full version of software will fix detected issues and repair virus damage caused to your Windows OS files automatically.

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

Read full review here.

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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.