Geek's Advice

KXDE ransomware uses encryption to lock all files on a computer

KXDE ransowmare is a malicious data-encrypting computer virus that originates from the infamous STOP/DJVU ransomware gang. It scans all computer folders and encrypts files found in them, then marks each of them with additional .kxde extension. To illustrate, a file originally named 1.jpg becomes 1.jpg.kxde and so on. To provide the victim with information on what happened during the cyberattack, the ransomware drops _readme.txt notes in several folders. The message left in these notes suggests that the only possible way to decrypt all files is by using KXDE decryption tool, which the victim can get after paying a ransom to cybercriminals.

The _readme.txt note contains explanation of what happened to the victim’s computer-stored files and cybercriminals’ proposal on how they can be recovered. The note suggests that all files, including images, videos, databases and documents were encrypted with strongest algorithm and unique key. According to the ransomware analysis, the currently used encryption mode combines Salsa20 and RSA-2048 algorithms. The message left by the attackers explains that there is no other way to recover files except of paying a ransom; if the victim plans to do so, one can contact the attackers via provided emails – support@sysmail.ch and supportsys@airmail.cc.

Going further into the ransom note contents, we can see that the criminals suggest testing the decryption service. They recommend sending one small encrypted file to them (preferably one that doesn’t contain valuable information) via email and also include the victim’s Personal ID which is provided in each _readme.txt file. The attackers promise to reply with a decrypted file version to prove that they can recover all of victim’s files. On top of that, they explain that the decryption tool price depends on how fast the victim gets in touch with the criminals. If the victim writes to the provided emails within 72 hours from the infection date, the decryption costs $490. If the victim hesitates for any longer, the price will rise to $980.

Victims of ransomware attacks lose the most valuable data in such events. Naturally, we keep personal memories, work or study files in our computers, and suddenly losing access to them can have disastrous consequences that can affect not only you, but your clients’ files as well (if you use your computer for work, for example). That said, paying a ransom might seem tempting. However, we strongly advise you NOT TO PAY THE RANSOM. The same idea is supported by the official FBI’s advisory for ransomware victims.

First of all, not all ransomware victims recover their data after paying a ransom. Moreover, paying a ransom is wrongful because it funds criminal operations, for instance, money allows them to employ more people, more skilled developers and distributors. Finally, if you decide to comply with criminals’ demands, you will be identified as a victim who is willing to pay up and possibly will be targeted again.

Data encryption isn’t the only malicious activity carried out by STOP/DJVU ransomware. Beware that this notorious malware travels along with Azorult or Vidar Trojans, both known for their capabilities to steal information from victim’s computer (for instance, your browser-saved passwords, cryptocurrency wallets, browsing history, cookies, etc). Moreover, they’re classified as Remote Access Trojans (RATs), which means that the attackers can control them remotely and perform activities such as viewing, deleting your files or downloading something to your computer (such as more malware).

All things considered, you should take action to remove KXDE ransomware virus and related threats from your computer to ensure your privacy is not at risk anymore. Therefore, we have prepared in-detail instructions on how to boot your PC in Safe Mode with Networking and start your chosen antivirus software from there. If you haven’t decided on one that you wish to use, we recommend relying on INTEGO Antivirus. Additionally, we advise downloading RESTORO and running a full system scan to identify which virus-affected system files can be repaired.

Ransomware Summary

REMOVE MALWARE & REPAIR VIRUS DAMAGE

Ransomware distribution techniques

Malware variants from the STOP/DJVU ransomware family, including KXDE virus, are known to hide in pirated software versions advertised online. The victims typically stumble upon them when looking for ways to illegally activate full versions of paid software. They can be found in rogue websites or downloaded via torrents. Unfortunately, such downloads often carry a malicious payload inside of them, resulting in a full data encryption on a computer. Victims who have been exposed to variants of STOP/DJVU variants report falling into a trap after downloading software cracks supposed to activate full versions of these popular programs:

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

If you still have a bad habit of using pirated software versions, we recommend that you quit such activities for your own safety. When in need for a specific software, visit its official website or a confirmed partner’s site for deals and discounts and get a legitimate license key from there. This way, you won’t expose your computer to risks that come with illegal software versions. Remember that legitimate software subscriptions are never greater in cost than hefty ransoms that cybercriminals demand, not even to mention additional damages associated with private data loss.

Another common ransomware distribution method that is also related to STOP/DJVU and other malware families is malicious email spam. Cybercriminals send out thousands of email messages to potential victims and attach a maliciously modified file to them, usually a document in DOCX, PDF or XLS formats. These scam emails usually follow a similar pattern – the sender claims to be someone from a well-known company, such as DHL, UPS, eBay, Amazon, or other, and invites the user to open the attached file as soon as possible and reply to the sender. Most of the time, the attachments are named as invoices, order summaries, parcel tracking details and so on.

The message typically contains typo mistakes and the sender doesn’t know your real name, so the scammer greets the recipient using the email address username. For example, if your email address is Eduard123@example.com, the scammer might use Dear Eduard123 as the greeting line. Most of the time, these emails are composed using automatic programs. However, the attackers also tend to use email spoofing techniques to display a different sender’s email address for the victims, so we strongly recommend that you read this article on how to identify spoofed email addresses.

Finally, victims of STOP/DJVU ransomware should stay away from suspicious online resources and people promising you decryption solutions. You should rely on trustworthy cybersecurity blogs only, and if these clearly state that there are no ways to decrypt files, it is that way. Do not fall into a trap of scammers who suggest you to download tools that can decrypt all versions of STOP/DJVU – these can hide additional malware. Moreover, watch out for scammers claiming they can recommend a “hacker” who can decrypt your files, and even worse, do not pay them if they ask you to do so. The only tools that can help victims of STOP/DJVU at the moment are created by Emsisoft and DiskTuna, and you can read more about them here.

How this ransomware operates

If you’re interested in modus operandi of KXDE ransomware virus, continue reading. This computer virus typically operates under its main process which is typically named with 4 random characters, for instance, 1GB6.exe or 9HN6.exe, but it also downloads some helper processes which are usually named as build.exe, build2.exe or build3.exe. Sometimes, it also downloads and runs a process under a name of winupdate.exe to display a fake Windows update screen for the victim while the main process is encrypting victim’s files.

Before starting the data encryption procedure, this ransomware performs a geolocation check first. An interesting detail about this virus is that it doesn’t encrypt files in computers located in several countries, including Ukraine, Russian Federation, Syria, Armenia, Tajikistan, Kazachstan, Kyrgyzstan, Belarus, and Uzbekistan. To check what is the infected computer’s geolocation, the ransomware requests a response from https[:]//api.2ip.ua/geo.json and saves it into geo.json file. This file contains details such as PC’s IP address, country, city, timezone, and more. You can see two different examples of how this file appears in the screenshot provided below.

Next, the ransomware creates a file named information.txt, which contains details about the computer’s hardware, installed software and actively running processes at the time of the attack. The ransomware also takes a screenshot of the desktop and sends them both to the Command&Control server. An example of information.txt contents are presented in the image below.

Next, the ransomware attempts to request an online encryption key from its server. If this fails, the virus switches back to offline encryption mode and uses a hardcoded key instead. It saves the encryption key along with victim’s Personal ID to bowsakkdestx.txt file, and the ID separately to PersonalID.txt file. Both of these are displayed below.

Speaking of SSOI ransomware encryption modes, they are divided into two – online and offline modes. When it comes to the online encryption type, it means that the malware has successfully obtained a unique encryption key and ID for the victim, which makes data recovery chances slim. Speaking of offline encryption mode, it indicates that the virus failed to obtain an encryption key from its server (for instance, due to Internet connectivity issues or if the server was down at the time of the request). Those subject to the offline encryption will typically notice t1 characters at the end of their PersonalID (a file located in C:\SystemID) and this indicates that there’s a possibility to recover all data in the future. Read more on how and when you can decrypt/repair STOP/DJVU encrypted data here.

After saving the encryption key, the ransomware begins encrypting all of victim’s computer files using a combination of Salsa20 and RSA-2048 algorithms. During this process, each affected file will be marked with an additional .kxde extension as shown in the screenshot below.

The virus also drops a copy of _readme.txt in every folder.

Finally, the ransomware alters Windows HOSTS file by adding a list of websites to block on victim’s PC. As a consequence, victim’s attempts to visit them will be unsuccessful. The web browser may respond with DNS_PROBE_FINISHED_NXDOMAIN or similar error.

Remove KXDE Ransomware Virus and Decrypt Your Files

In an unfortunate event of becoming victim of a ransomware attack, the most important step is to erase all traits of the malware that compromised your computer. That said, we encourage you to follow the steps given below to remove KXDE ransomware virus safely. If you’re unsure which antivirus solution you can rely on, our team strongly recommends INTEGO Antivirus. Additionally, we suggest downloading RESTORO to repair virus damage inflicted on Windows OS files.

After KXDE ransomware removal, you may want to take these recommendations into consideration:

• Report cybercrime incident to a local law enforcement agency.
• Use data backups to restore some of your files.
• 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

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.