Geek's Advice

RUGJ ransomware tries to extort you after encrypting your files

RUGJ ransomware is a variant of STOP/DJVU ransomware family. This computer virus is designed to encrypt all of your personal files stored on a computer using Salsa20 and RSA-2048 encryption algorithms. As a result, these files become impossible to open, view or edit. While encrypting your files, the malware also appends their names with .rugj extension and drop _readme.txt ransom note in the containing folder. For example, a file originally called 1.jpg will appear as 1.jpg.rugj after being encrypted. The note left informs the computer user that the only way to recover files is to purchase RUGJ decryption tool and unique key from the cybercriminals. They suggest contacting them via manager@mailtemp.ch or supporthelp@airmail.cc for further information, adding that the decryption price ranges between $490-$980 depending on how quickly the victim writes to them.

RUGJ ransomware virus was developed with sole intention of extorting computer users after taking their files hostage. While encryption itself is a legitimate process used to secure information transmission, hackers make a bad use of it to illegally block access to computer user’s files. The attackers suggest contacting them as soon as possible, offering a 50% discount on the decryption service if the victim does this within 72 hours. Otherwise, the victim has to pay $980 for data decryption. The criminals won’t accept no other payment method than cryptocurrency as this helps to keep their anonymity.

Speaking of encryption type used, the virus locks your files using Salsa20 algorithm, thus securing the key used to modify your files with another RSA-2048 key. This key can be offline or online, based on virus’ success to communicate with its Command&Control server. You can learn more about decryption options or learn how to repair audio and video files using this guide.

The _readme.txt note dropped by ransomware is basically a message from virus’ developers. It explains that victim’s files such as pictures, databases, documents and other important files were encrypted with the strongest encryption and unique key. According to this note, the only possible way to recover your files is following the criminals’ instructions and paying a ransom. The attackers also introduce the pricing of it and suggest sending one encrypted file to them via email for test decryption. The file, however, should not contain any valuable data as the attackers do not want you to recover anything important. Their aim is to prove you they can decrypt your files and encourage you to pay up.

Cybersecurity experts worldwide do not recommend paying a ransom to Internet criminals. The same recommendations are provided by FBI. Some of the reasons why you shouldn’t listen to crooks’ demands are listed below.

• Paying a ransom doesn’t guarantee that your files will be decrypted, no matter what the crooks promise you. Even if they prove their ability to decrypt your files via test procedure, they can still not provide you with required tools after you pay.
• Collecting ransoms from computer users is what keeps the whole ransomware business thriving. If people stopped paying up, there would be no reasons for criminals to continue their activities.
• Each year, cyber attackers collect millions of US Dollars by extorting computer users with the help of ransomware. The idea of earning a lot of money while remaining anonymous lures other people to join these criminal activities.
• STOP/DJVU ransomware versions such as RUGJ virus are known to drop information-stealing Trojans on compromised computers, although this isn’t mentioned in _readme.txt ransom note. Two of known variants are called VIDAR and AZORULT. Information they are capable of collecting can be used against you for further blackmailing.

If you’ve fallen victim to a ransomware attack, we suggest you to secure your computer as soon as possible. Keeping an up-to-date antivirus software on your computer is a must; ideally, one that provides real-time protection. Therefore, we recommend you to remove RUGJ ransomware virus and related malware using AV software of your choice. If you do not have one, we strongly recommend INTEGO Antivirus which has been approved by independent AV test labs and has excellent malware detection rate. Additionally, you may want to download RESTORO to repair virus damage on your Windows operating system files.

Ransomware Summary

REMOVE MALWARE & REPAIR VIRUS DAMAGE

More technical details of ransomware activity on your PC

After landing on the target system, RUGJ ransomware launches a several executables named build.exe, build2.exe and similar. At the same time, the virus tries to conceal its activities by displaying a fake Windows update window (winupdate.exe process). In the meantime, the malware prepares for the actual data encryption.

The virus collects some hardware/software information about the infected host, such as user name, operating system version, names of programs installed and other details. Additionally, it connects to https[:]//api.2ip.ua/geo.json and as a response gets information such as computer’s IP address, country code, city, zip code, longitude, latitude and time zone.

First of all, the ransomware checks whether the infected computer is located in a country that isn’t on the exception list. The countries that this virus exempts from encryption are Russian Federation, Syria, Armenia, Tajikistan, Kazachstan, Kyrgyzstan, Uzbekistan, Ukraine and Belarus.

However, if the target’s location isn’t one of the listed countries, the ransomware then proceeds to decide which encryption key to use – online or offline. It attempts to get the online encryption key from its C&C server, but if this fails, it uses a hardcoded offline key instead. The offline key is identical for all victims of offline encryption, therefore, it gives such victims a slight chance of recovering their files as explained here. The virus saves the online encryption key to a file called bowsakkdestx.txt along with victim’s personal ID, which is also saved separately into PersonalID.txt file and included in every ransom note.

You can determine whether you were affected by offline key if your personal ID ends in t1.

Once the encryption key is determined, RUGJ ransomware begins scanning folders and encrypting all files found on them using Salsa20 algorithm, thus securing the key used in this encryption with the online or offline RSA-2048 key. The virus also marks affected files with additional extension and drops ransom notes along the way.

Ransomware-type viruses often take additional measures to prevent the victim from restoring files, so they tend to delete Volume Shadow Copies from the system using the following Command Prompt task:

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

Moreover, this ransomware modifies Windows HOSTS file to block a list of computer and cybersecurity related websites and online forums. The malware maps these domains to localhost IP to cause DNS_PROBE_FINISHED_NXDOMAIN error. The reason why it does so is because the criminals want to cause as much frustration as possible and shut out the victim from possible help resources on the Internet.

Finally, the virus drops additional malware on the system, often times VIDAR or AZORULT. Both of these Trojans are known for their capabilities of stealing private information, such as login credentials, browser history, browser-saved passwords, application logins (Steam, Telegram and more), cryptocurrency wallets and banking credentials.

Overview of methods used for distribution of ransomware-type viruses

Ransomware-type threats typically get into victims’ computer by deception. The most common attack vectors are malicious torrents, exploits, fake software update ads or installers, deceptive decryption tools and malicious email attachments. When it comes to STOP/DJVU versions like RUGJ virus, the main distribution method is malicious torrents such as pirated software copies.

Cybercriminals target users who tend to have bad habits of downloading illegal software copies and trying to activate their full versions for free. These torrents can be found in various torrent listings online. The malicious ransomware payload can hide in a software crack, key generator or another tool used for activating full software or game versions. Victims of this ransomware strain reported getting infected after downloading these software torrents:

• Adobe Photoshop;
• Corel Draw;
• Fifa 20;
• Tenorshare 4ukey;
• AutoCad;
• Opera browser;
• Internet Download Manager;
• VMware Workstation;
• Cubase;
• Adobe Illustrator;
• League of Legends;
• KMSPico (illegal Windows activation tool).

This list is not finite. What worsens the situation is that users also often ignore their security software warnings about such downloads, thinking that these are simply false positives for anything that contains a crack. Although this might be true in certain cases, you really shouldn’t try to install software illegally. Most of such torrents can contain various malware versions, including Trojans, backdoors, keyloggers and other threats that pose a severe risk to your privacy and data. Some of the malware might not show its presence immediately, as cybercriminals can set an idle time on malware so that it executes after several days or weeks.

Our recommendation is to support legitimate software developers rather than greedy criminals. Besides, the cost of software license is always lower than an average ransom that cyber crooks demand paying. If you want to get a clean copy of a game or program, download it from an official website or approved partner’s site. This is the only way to get safe software versions.

Another technique used for ransomware distribution is based on malicious email attachments. To carry out such attacks, cybercriminals compose documents in popular formats such as DOCX or PDF and leverage macro functions or JavaScript code support in them. Such email attachments can be named as “Invoice”, “Order Details” or similar to trick the victim into thinking it is a safe document; often times, the email message urges to open the attachment and reply to the sender as soon as possible. Nowadays, scammers can even spoof their email to make it appear legitimate. For this reason, we strongly recommend you to learn how to identify spoofed email address. In general, think whether this email was really intended for you or is it someone trying to trick you to open something that you shouldn’t.

Victims of STOP/DJVU ransomware variants should also stay away from suspicious websites offering miracle decryption tools, because it is simply another measure to distribute other ransomware strains such as ZORAB. Please keep in mind that in case a legitimate company manages to create a decryption tool, it will be available on well-known and reputable websites and also covered by trusted news sites as well. There is no need to browse through rogue websites as these certainly won’t provide you with such tools.

Remove RUGJ Ransomware Virus and Recover Your Files

If you have fallen victim to ransomware attack, the first thing that we recommend doing is cleansing your computer from malware. Deleting infectious files and altered settings can be difficult for inexperienced computer users, so we typically advise doing it automatically. You can find a tutorial on how to remove RUGJ ransomware virus below. Make sure you use an up-to-date antivirus for this task; if you do not have one yet, consider using a well-reviewed security software like INTEGO Antivirus which will also secure your computer with real-time protection. Additionally, downloading and running a scan with RESTORO might help to repair virus damage to Windows OS files.

In case RUGJ ransomware removal is complete, please read the following suggestions by our team:

• Inform your local law enforcement agency about cyber attack incident that happened to you.
• You can recover your data using backups, but make sure you remove all threats from your computer using robust antivirus before that.
• Learn how you can decrypt or repair files affected by STOP/DJVU versions.
• Change your passwords for as many accounts as you used on your computer, including browser saved ones, also Steam, Telegram and other apps.

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.