Geek's Advice

VOOM ransomware is malicious computer virus that takes your personal files hostage

VOOM ransomware is a computer virus recently released by the STOP/DJVU ransomware gang. The aim of it is to encrypt all files stored in the compromised computer and mark them with .voom extensions. To illustrate, a file previously named as 1.jpg will be renamed to 1.jpg.voom and the same applies to all filenames. Once all data is encrypted, the virus drops several _readme.txt notes throughout the system to inform the victim about what happened. According to the note, all of victim’s private data was encrypted, and the only provided solution to the current situation is paying a ransom and receiving VOOM decryption tool from the criminals.

Contents of _readme.txt warn the computer user that all files stored in the infected computer have been encrypted with the strongest encryption algorithm and a unique key. In particular, the ransomware targets all image, video, music, document formats, as well as archives. Malware analysts point out that STOP/DJVU variants are programmed to use a combination of Salsa20 and RSA-2048 for data encryption. The ransom note then suggests purchasing a decryption tool from the criminals, which is nothing else than a pure extortion; in other words, in order to recover files, the victim is asked to pay a ransom. The ransom note also contains two email addresses that can be used to contact the criminals – support@sysmail.ch and supportsys@airmail.cc.

The cybercriminals also specify that victims who contact them within 72 hours (3 full days) can get a 50% discount on the initial ransom price. In other words, the attackers may provide the decryption tool for $490. If the victim delays writing to the attackers and paying the ransom any longer, the decryption service price will be set to $980. The note also suggests attaching one encrypted file to the email, promising to reply with a decrypted version of it. This test service is provided in order to encourage the computer user to pay the ransom.

After contacting the criminals via email, the victim will find out that the crooks only accept cryptocurrency as a form of payment. Such transactions help them to remain anonymous and prevent law enforcement agencies such as FBI from discovering their location and identities.

Ransomware-type viruses sure do encrypt important data on victim’s computer, and one might start considering paying the ransom. However, our team recommends following FBI’s recommendations regarding ransom payments, and they clearly state that paying a ransom is NOT A RECOMMENDED CHOICE. There are several arguments to explain why: first of all, paying a ransom does not guarantee data recovery. There are numbers of cases where ransomware victims paid the ransom and never received the decryption tool, or its functionality was faulty. Moreover, sending your money to the attackers only helps them to create more malware and infect even more computers. Finally, if you pay up, you might be added to potential targets list and identified as one who is willing to pay money to cybercriminals.

On top of that, STOP/DJVU ransomware variants are known to travel along VIDAR or AZORULT Trojans, both widely known as information-stealers that cybercriminals can control remotely. These malicious tools can be used to steal your login credentials for various websites or apps, browsing history, banking details, cryptocurrency wallets and also view, edit, or download files. With their hands on such tools, the criminals can extract information that might come in handy when blackmailing computer users.

All things considered, we recommend that you remove VOOM ransomware virus as soon as you can. For this matter, use a trustworthy software of your choice. Our team recommends using RESTORO for repairing virus damage on Windows OS files.

Ransomware Summary

REMOVE MALWARE & REPAIR VIRUS DAMAGE

Ransomware distribution methodology

STOP/DJVU ransomware variants such as VOOM virus typically await in pirated software downloads advertised in various rogue websites online as well as torrent listings. Therefore, computer users who are looking for ways to install and activate paid software versions for free are more susceptible to computer infection and complete data encryption. Victims who were infected with previous versions of this infamous ransomware family report getting their data encrypted after downloading an illegal version of these popular programs:

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

We strongly recommend that you avoid shady websites when looking for a specific software or game version. The only way to get legitimate software license is to pay for it; you can visit the official software vendor’s website or a confirmed and reliable partner’s site for deals and discounts. If you’re trying to save money, remember that exposing your computer, data and personal information to cybercriminals will result in much greater expenses at the end.

Malicious email spam is another technique used by ransomware distributors to reach potential victims. The criminals usually create a convincing message and attach a file to it. The most common fraud scheme involves pretending to be a legitimate company, such as DHL, Amazon, eBay or another that is sending an invoice, order summary, or parcel tracking details. The attackers expect the victim to open the attached file, which usually comes in DOCX, PDF or XLS formats. However, doing so activates a malicious script hidden in it and downloads and runs the ransomware on the computer.

These scam emails are usually generated using automatic programs and since the criminals don’t usually know your full name, they tend to address you using your email address username. For example, if your email address is Robert123@example.com, the crook might use Dear Robert123 in the greeting line. Moreover, you should not completely rely the sender’s email address, even if it looks legitimate. Cybercriminals tend to use spoofed email addresses, and this technique makes the sender’s email address appear different than the original one.

Finally, victims of STOP/DJVU should know that the only tools that are capable of decrypting/repairing files affected by this ransomware are created by Emsisoft and DiskTuna, and you can read more about them here. Any other tools suggested by rogue websites or scammers online can infect your PC with even more malware. We also recommend you to stay away from scammers advertising “hackers” who can decrypt your files. All they can do is swindle you out of hundreds of dollars and vanish into a thin air. Think about it this way – if legitimate cybersecurity companies cannot help victims of ransomware due to technological complexity of encryption used, some random “hacker” won’t, as well.

Explanation of ransomware activities on your computer

This article section explains how the STOP/DJVU malware operates on the infected system. Upon arrival on the victim’s computer, VOOM ransomware virus launches in a form of a executable named with 4 random characters, such as 1B7B.exe or similar. It also downloads several additional processes (build.exe, build2.exe or build3.exe) to help itself perform various malicious activities on the computer. In some cases, the ransomware also runs a fake winupdate.exe process which displays a window imitating OS update procedure progress.

An interesting detail about this ransomware strain is that it doesn’t encrypt data in computers situated in the following countries: Ukraine, Russian Federation, Syria, Armenia, Tajikistan, Kazachstan, Kyrgyzstan, Belarus, and Uzbekistan. To check this, the ransomware connects to https[:]//api.2ip.ua/geo.json and saves the response in geo.json file. The said file contains computer’s IP address, city, country, timezone and related details as shown in the examples below.

If any of the aforementioned countries are detected, the virus stops its activities. If not, it proceeds to collect more information about the computer, such as hardware specifics, installed programs and active processes. Such data will be saved into information.txt file and forwarded to the criminals’ Command&Control server. You can see a screenshot of this file down below.

The ransomware then attempts to connect to its C&C server to request a unique encryption key for the victim. If the Internet connection is poor or the server is down, the ransomware switches to offline encryption mode and uses a hardcoded offline key for the data encryption. The key and victim’s personal ID will be saved into bowsakkdestx.txt file and the ID individually to PersonalID.txt file and repeated in every ransom note. You can see examples of the described files below.

Here’s what you need to know about the encryption modes used by this ransomware: they are categorized into offline and online types. When an online key is used, it means that the key is entirely unique per victim, which leaves no chances to recover encrypted files without a backup or paying the ransom.

The offline encryption mode, however, is used when the ransomware fails to obtain the unique key and uses a key hidden in the ransomware itself. That said, the same offline encryption key is used for all victims of offline encryption; therefore, if someone pays the ransom, successfully receives a decryption key and shares it with cybersecurity experts from Emsisoft, their decryption key gets updated and becomes capable of decrypting files affected by offline encryption for all victims of VOOM ransomware. You can check for updates about the tool here.

The ransomware encrypts all files using Salsa20+RSA-2048 encryption algorithms and appends .voom extension to their full names. You can see how encrypted files appear below.

During the attack, the ransomware drops _readme.txt note in every data folder.

Lastly, the virus modifies Windows HOSTS file by uploading a list of websites to block on victim’s computer. As a consequence, victim’s attempts to reach these websites will be effectless. The web browser may respond with DNS_PROBE_FINISHED_NXDOMAIN or similar error.

Remove VOOM Ransomware Virus and Decrypt Your Files

If your computer was compromised by the described variant of STOP/DJVU, we strongly recommend you to boot your PC in Safe mode with Networking using instructions provided below and remove VOOM ransomware virus using a malware removal program of your choice. We recommend using RESTORO for deleting malicious files and repairing virus damage to Windows OS files.

After VOOM ransomware removal, check the following recommendations:

• Let local police office know about the ransomware attack on your computer.
• Use data backups to recover as many files as you can.
• Find out ways STOP/DJVU-encrypted files could be decrypted or repaired.
• Change all passwords used on the infected computer.

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

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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.