Geek's Advice

RTGF ransomware locks your files, demands money for their decryption

RTGF ransomware is a malicious and highly damaging computer virus variant arising from STOP/DJVU ransomware group. This threat encrypts files contained in the PC it infiltrates and also appends .rtgf extension to each file name. To illustrate, a file that was earlier named as 1.jpg will be automatically renamed 1.jpg.rtgf, and the process will be repeated on all data. The ransomware also replicates a ransom note known as _readme.txt in all the folders. The note contains a message from those behind a ransomware attack, who suggest that the only way to get RTGF decryption tool is to pay a large ransom to the attackers.

The ransom note emphasizes that RTGF ransomware virus has successfully encrypted all files contained in the computer, such as documents, pictures, and various other data, while making use of a very strong and unique encryption key. According to the message, the victim has no other choice than to pay the ransom so they can send across a decryption tool. The message contains two email addresses of cybercriminals – support@sysmail.ch and helprestoremanager@airmail.cc.

The crooks also include decryption service prices as well as terms and conditions they expect the victim to comply with. They claim that the amount of money that victim needs to pay as ransom depends on how soon one will be able to make the payment. For instance, the criminals state categorically that victims can pay just 50% of the ransom fee if only they can do so within a maximum of 72 hours or 3 days. In other words, instead of the intended $980, they would now pay $490. However, once the given time elapses, only the full ransom fee would be acceptable.

Nevertheless, should the victim decide to reach out to them, they will come up with more conditions by informing that payment can only be made by purchase of cryptocurrency and transferring same to a wallet address they would make available for the purpose. The apparent reason why they use such an anonymous channel is to cover their tracks and prevent law enforcement agents from coming after them.

To assure the victim and spur them into making payment, they sometimes request for parts of the encrypted data to be sent to them for test decryption but they will also be quick to instruct that such excerpt must not contain any information that could be perceived as vital to the victim.

Regardless of the situation, our in-house cybersecurity experts warn victims not to comply with their demand but should instead follow FBI’s guidelines pertaining to ransom payments, and the directive is NO TO RANSOM PAYMENTS! There are several reasons for taking this decision but the most important ones are listed below:

• There is no guarantee your lost data will be restored even after paying huge sums of money as ransom.
• Paying ransom to cybercriminals encourages them to continue in their criminal activities.
• More funds in the hands of cybercriminals would enable them to employ additional rogue IT experts, thereby worsening the situation.
• By law, it is illegal to pay ransom.

In addition to the encryption, the virus is infamous for dropping certain Trojans such as VIDAR and AZORULT that are notorious for stealing vital information like banking details, cryptocurrency wallets, software login details, passwords etc. on the already compromised PC which could lead to further scams including blackmails or stealing.

Victims of this malware should as a matter of urgency remove RTGF ransomware virus from the infected PC. The recommended way to go about it is to boot such a computer into Safe Mode with Networking mode before running genuine software antivirus on it. Endeavor to use only quality antivirus software and if you’re not sure about which brand would be suitable, then we recommend INTEGO Antivirus. In addition to that, you should also download RESTORO to help restore damaged Windows OS files.

Ransomware Summary

REMOVE MALWARE & REPAIR VIRUS DAMAGE

Ransomware distribution techniques often used by cybercriminals

The most common technique used by cybercriminals in spreading STOP/DJVU ransomware variants including RTGF virus is by uploading malicious software copies to online torrents platforms. Some of these pirated software contents include popular software contents as well as so-called “cracks” and key generators. When unsuspecting users who want to cut corners download these pirated software contents in their PC, they end up triggering ransomware attacks. As reported by victims, here is a list of the most popular ones used by cybercriminals:

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

Computer users that have formed the habit of going to online torrents platform are hereby advised to stop such risky behavior forthwith because they’re only endangering their PC because ransomware attack could be triggered at any moment. The motive of cybercriminals for uploading these illegal contents are not genuine, instead they use it as bait to prey on their victims. Also, such illegal download of software contents is a copyright infringement and is punishable by law.

Instead of going through all these, it is a lot better to support the growth of the industry by downloading only from the official pages of the original content producers or their third-party affiliates. Whatever price of a legitimate software license is, it is always little compared to the outrageous amount usually demanded by cybercriminals. In addition to that, you stand no risk of losing sensitive and vital documents to cybercriminals.

Another method by cybercriminals in spreading ransomware is through malicious email attachments whereby they would compose “real” looking emails while claiming to be an acquaintance or assuming the identity of any popular brand. The typical ones they often impersonate are Amazon, eBay, DHL, UPS etc. They will also make use formats like XLS, DOCX, PDF or other similar ones that allow JavaScript and macro functions that can transport and trigger payload in other computers.

The worrisome part is how to detect which email is actually genuine or emanating from cybercriminals considering the extent they go in adapting their own fake emails to appear very much genuine ones. In addition to that, they tend to give it compelling names like any other random ones such as Invoice, Tracking Details, or Order Summary among other similar ones. Alternatively, they may decide to make use of email spoofing techniques in obfuscating the actual sender’s address. Whatever method they may opt for, it would be in your best interest not to open any email you’re not sure of its source. Any unexpected email, especially one with a suspicious originating address should be considered a red flag and not opened recklessly.

Lastly, becoming infected with any variant of STOP/DJVU ransomware is not enough reason to throw caution to the wind and start visiting dubious websites that claim to offer decryption solutions. More often than not, most of these sites are opened by crooks who want to spread other ransomware variants such as ZORAB disguised as fake STOP/DJVU decryptors. At the moment, only DiskTuna and Emsisoft have proven to offer decryption tools that actually work. Downloading other fake ones would most likely lead to double file encryption.

More information about the ransomware

For those that may be wondering about what actually happened to their computer during RTGF ransomware attack, this section will explain it in more details. The first thing the malware does is to set up build.exe and build2.exe executables and also winupdate.exe (the prompt that displays fake Windows page). The virus then makes a connection with https[:]//api.2ip.ua/geo.json before saving the response in geo.json file. Afterwards, it would extract more details concerning the computer such as its geolocation, time zone, zip code, longitude and latitude and would save them in the geolocation-related data. Shown in the image below is an example of geo.json file.

The malware then creates another file that contains hardware details, installed software, and other active processes – information.txt.

In addition to that, the virus will make use of the geolocation information about the infected computer to compare with a list of their own encryption-exempted countries which include the following countries: Russia, Ukraine, Syria, Armenia, Tajikistan, Kazachstan, Kyrgyzstan, Uzbekistan and Belarus. If it happens that the computer is located in any of these countries, they would immediately abort their mission. However, if it indicates negative, the ransomware will move to the next level by extracting online encryption key from their server and the victim’s ID before saving them both in the bowsakkdestx.txt file and the ID separately the to PersonalID.txt file. Shown here are examples of these files.

Peradventure the virus couldn’t extract online encryption key from the server, it will opt for the use of hardcoded offline key and it will be the same for all victims provided their PC’s were infected with the same variant. You can detect if an offline key was used if t1 characters appear at the end of the personal ID, and the implication is that .rtgf files could be decrypted someday. More details about it is provided below.

The ransomware would now commence data encryption procedure by scanning every folder and encrypting them with Salsa20 before using RSA-2048 to lock the encryption key. The virus also adds .rtgf extension to make encrypted files distinguishable.

A picture of _readme.txt ransom note that is typically left in every folder is shown below.

Afterwards, the virus will delete Volume Shadow Copies using the Command Prompt task as shown here:

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

At last, the virus will add certain domains to Windows HOSTS file and equally map them to local host IP thereby effectively preventing the victim from having any access to the blacklisted sites. The error message DNS_PROBE_FINISHED_NXDOMAIN may appear any time attempt is made to open them. It appears that the attackers blacklist some websites in order to prevent the user from reaching help regarding ransomware incident.

Remove RTGF Ransomware Virus and Get Back Your Files

The first thing to do following such a severe computer infection is to remove RTGF ransomware virus without any delay. For this task, we recommend using INTEGO Antivirus after booting your PC in Safe Mode with Networking. Afterward, you may be interested to download RESTORO to repair virus damage to Windows OS files. Once that is successfully done, the victim should follow these steps recommended by our team as outlined below.

• Immediately report to any relevant government law enforcement agency situated close to you.
• Make use of any data backup means available to you in restoring your lost data.
• Look for possible ways your files could be decrypted.
• Change all passwords that were remotely or directly used on the compromised computer as soon as possible.

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.

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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.