Geek's Advice

MUUQ ransomware uses stealthy techniques to take files on a computer hostage

MUUQ ransomware is a computer virus designed to lock all files on the target system with the help of RSA Salsa20 algorithm. The virus is a variant of STOP/DJVU ransomware family and its sole purpose is to make the files inaccessible to the victim, then demand a hefty ransom. During the attack, the malware marks each file with .muuq extension and leaves _readme.txt notes behind. To illustrate, a file originally called 1.jpg becomes 1.jpg.muuq after being encrypted. As explained in the _readme.txt file, cybercriminals who operate the malware distribution suggest selling .muuq decryption tool for a specific price which depends on how quickly the victim contacts them. If the victim writes to provided emails (manager@mailtemp.ch or managerhelper@airmail.cc) within 72 hours, the decryption will cost $490 in Bitcoin, otherwise – $980.

Developers of MUUQ ransomware seek to extort computer users as doing so is easier than earning money legally. They aim to lock years of work, study progress and personal memories using strongest military-grade encryption. During the attack, the virus locks first 150 KB of file before jumping on another one. The way this virus encrypts files allows repairing certain file formats. The algorithm is set to leave _readme.txt note in every directory so that the victim could easily notice it.

The said note informs that all of computer files are encrypted and that the virus’ developers suggest purchasing MUUQ decryption tool for $490 (if paid within 3 days) or, if the victim hesitates or takes a little more than 3 days to collect money, it will cost $980 for the victim. Needless to say, the attackers expect to receive the money in Bitcoin as this keeps the transaction untraceable and won’t come in handy when trying to find the perpetrators’ identity. However, there are more than enough reasons not to pay the ransom as suggested by many cybersecurity experts worldwide, as well our team, and FBI:

• Paying the criminals might result in a simple money loss as the attackers can refuse to help you after swindling the ransom from you. In other scenario, the tool they might provide can simply fail to work.
• Remember that it might be illegal to pay a ransom in your country.
• Ransomware-related cybercriminals make millions in USD each year, and these insane money amounts keeps pushing them forward and expanding their operations. Besides, the possibility to remain anonymous and earn a lot of money lures other people to join these illegal operations. Please, do not contribute to the growth of this by paying a ransom!
• Keep in mind that STOP/DJVU versions such as MUUQ virus tend to drop information-stealing remote access Trojan that can silently collect all sorts of private information from your computer and transfer it to criminals. This can lead to further blackmail attempts and more money loss. Do not believe that problems will stop if you pay the ransom.

REMOVE MALWARE & REPAIR VIRUS DAMAGE

Ransomware mechanism explained: what has been done to your computer

MUUQ ransomware runs a process called winupdate.exe, which mimics a Windows update window with a progress bar in it. However, at the same time the malware runs a 4-char named executable which encrypts all files on the target system. Additionally, the virus deletes Volume Shadow Copies from the computer, ensuring that these will not longer be usable when trying to access System Restore points. The virus executes the following task via Command Prompt to delete them:

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

Finally, the malware edits Windows HOSTS file, which maps hostnames to IP addresses. The virus adds a list of website names here and maps them to victim’s localhost. Consequently, the victim runs into DNS_PROBE_FINISHED_NXDOMAIN error when trying to open any of these sites. Apparently, the malware operators are trying to isolate the victim from relevant attack-related information online, as the websites it attempts to block all are related to computers, cybersecurity or self-help forums. After the infection, the computer user might also find several text files dropped by the ransomware – bowsakkdestx.txt (might be named differently), a file that contains the public key (used for data encryption) and victim’s identification string. Another file the user might find is called PersonalID.txt, a file that only contains victim’s ID.

If you’ve accidentally launched this ransomware on your computer, you should know something that’s have not been mentioned in the _readme.txt note. Unfortunately, this virus travels along AZORULT Trojan, a password-stealing menace that can be controlled remotely. Some of its functions are listed below. Please remember that such actions can cause a lot of harm to your computer, and stolen data might be used to blackmail you further.

• Downloading malware to the computer and running it;
• Stealing Steam, Telegram login credentials;
• Viewing or deleting files on victim’s computer;
• Stealing cryptocurrency wallets;
• Stealing browser cookies, saved passwords, browsing history and more.

We strongly recommend you to take actions to recover after computer infection as soon as possible. Our team recommends using a professional antivirus to remove MUUQ ransomware virus first. For this matter, you might want to use robust software with real-time protection to block malicious downloads from now on – INTEGO Antivirus. Once all malware is gone, we suggest scanning with RESTORO to repair virus damage on Windows OS files.

Ransomware Summary

REMOVE MALWARE & REPAIR VIRUS DAMAGE

Ransomware distribution scheme explained

Computer malware that arises from STOP/DJVU virus family is known to spread via malicious torrent downloads mainly. To put it simply, the virus often hides in various software cracks. For example, if you are someone who tends to look for ways to activate paid software for free, you definitely risk falling victim to MUUQ ransomware attack. Victims who have been attacked by these ransomware viruses previously have reported software they tried to download illegally and as it turned out, it contained ransomware:

• Office 365;
• Adobe Photoshop;
• Autodesk Sketchbook;
• CorelDRAW;
• Cubase;
• Wondershare Filmora;
• Adobe Illustrator;
• KMSPico and many more.

Cybersecurity experts recommend avoiding illegal downloads at all costs. People behind ransomware attacks know that computer users are trying to save money by downloading cracked software versions, however, doing so can result in much bigger expenses rather than paying for legitimate and secure software version. What is even worse is that many computer users proceed to open such downloads even if their security programs advise against doing so.

Another popular way to spread computer viruses is by sending malicious email spam to masses of people. Virtual perpetrators get their hands on email lists (usually made available via various data leaks and uploaded to dark web forums) and send specifically crafted documents to them along with a short message urging to open attached contents. The attachment might arrive in various file formats, such as DOCX, XLS, PDF, but it can also arrive in a .bin or .ace file format. Our recommendation is to avoid emails that you did not expect to receive and look out for such red flags informing you about a potential attempt to compromise your computer:

• Stay away from emails suggesting that you have won in a lottery you never participated in;
• Emails suggesting that there is a pending payment that needs to be completed immediately;
• The sender claims to be from reputable company yet the email message and inserted logos seem sketchy;
• Sender’s email address seems suspicious;
• The message tone is urgent and asks to open attached contents as quickly as possible;
• The sender’s email address appears spoofed;
• You email box provided marks the message as spam.

Finally, computer users who have already fallen victim to ransomware attack should beware of fake decryption tools available in malicious sites online. Cybersecurity experts warn that desperate attempts to find decryption tools that are simply non-existent can result in a second ransomware infection, because the cybercriminals tend to disguise malware as decryption tools. One ransomware strain that’s been known to hide in false STOP/DJVU decryption tools is called ZORAB.

Remove MUUQ ransomware virus and decrypt or repair your files

To protect your computer from further infections and also to remove MUUQ ransomware virus along with other malware, we recommend using a professional antivirus software of your choice. Our top pick is INTEGO Antivirus, a program that has VB100 certification and can block malicious downloads and prevent you from accessing deceptive or phishing websites. The second step we recommend taking is downloading RESTORO to repair virus damage on Windows OS.

After a successful MUUQ virus removal, take a look at these recommendations on things you should do after experiencing a ransomware attack:

• Let your local authorities know about the ransomware attack – register the case according to given recommendations;
• Take a look at this guide on how to decrypt or repair files affected by STOP/DJVU versions;
• Change all of your passwords, especially for those websites that you chose to remember login credentials for in your browser;
• Consider creating data backups from now on;
• Invest in reliable antivirus with real-time protection.

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.