Ransomware is a growing plague running in the forefront of internet-borne extortion. Last few years saw a remarkable uptick in this particularly nasty genre of system attack. The scale & automated nature of Ransomware attack makes it popular in the cyber crime world. Profitable through economies of scale, a successful Ransomware attack allows criminals to demand payment from victims in exchange for restoring access.
Djvu Ransomware also known as .djvu files virus is a devastating file locker that was released in December 2018 in an attack campaigns against computer users worldwide. In order to inhibit users from accessing valuable data, the Ransomware interferes with essential system settings & encodes certain types of files. The infected files are appended with .djvu extension and a ransom note is dropped to inform users about the attack. The note further demands a whopping ransom fees from victims to retrieve the encrypted files which is a delusion!
Djvu Ransomware- A variant of STOP virus family!
Djvu Ransomware is a spin-off of STOP virus family, a data-locker that first made its appearance in December 2017. STOP Ransomware leverages a combination of AES & RSA encryption algorithm & adds .STOP file extension to encrypted files. The Ransomware has constantly emerged since its inception releasing new versions. The basic difference among these variants is the extension they use to mark the corrupted files. The list of extensions discovered of STOP virus family includes:
- .djvu etc
Djvu Ransomware- Threat Behavior
Djvu Ransomware is a threat that invades computer systems with the purpose to encrypt certain types of files. The files it targets include:
- Text files
- Image files
- Document files
- Video etc
This is the most active version of STOP Ransomware that demands a ransom of $300-$600 for data decryptor.
The Ransomware is designed to implement significant changes in essential system components that enable it to manipulate various system functionalities. For Instance it drops several malicious files located in following system folders:
The victim is informed about the attack via a ransom note that compels users to contact crooks via email@example.com, firstname.lastname@example.org, email@example.com or similar email addresses. The message is contained in a file called _openme.txt which reads as:
The decryption might be hard to perform even for the highly-experienced users. However, victims are recommended not to rush to pay the criminals. Threat actors often try to scam their victims by providing them false promises. Users are therefore advised to act wisely & follow the safety regulations to avoid any mishap.
Maintaining regular data backup and storing them on a remote server or unplugged storage devices is utmost important to avoid unforeseen circumstances.
Djvu Ransomware- Distribution Techniques
The cybercriminals use various strategies for malware distribution which include –
- Software Bundling: Software bundling is the process in which a malicious program is distributed with other free software, to get an unnoticed entry into your computer system. When a user installs a free application, the malicious programs gains a front door entry with the free application, the user has downloaded. Thus, it is a good idea to keep an eye on the installation screens while installing these free applications.
- Infected Storage Devices: Your system can also get infected by using removable media such as USB hard drives and jump drives without scanning them with an anti-virus.
- Spam Emails – Spamming is the most economic and common method used for the distribution of such malware. The targeted users get genuine looking emails which contain .doc, .txt, and other similar attachments. These attachments can be named as anything which can grab the user’s attention and triggers him/her to open the attachment. As soon as the user opens this attachment, the malware infects the user’s computer system.
- Malicious Websites or Malevolent Advertisements: The malicious websites are the ones which are created just for promoting the malware infections. Such websites include but are not limited to porn sites, torrent sites and other free downloading platforms. By visiting such websites, the adware infects the user’s computer without permission. Fake advertisements and updates like Flash player and windows updates which ask the user to update to the latest version are a few examples. When the users click on such links, their computer system gets infected. That is why, it is highly recommended to resist clicking on such links. Also avoid clicking on advertisements offering free stuff such as Win an iPhones, cars or free overseas trips etc.
Targeted Operating System: Windows
Symptoms: User’s files are encrypted. All locked files are appended with .djvu extension after the encryption and hence cannot be accessed by the user.
How to avoid Djvu Ransomware infiltration in the System?
Step A: Remove the Services Installed By Djvu Ransomware from the System using Safe mode with Command Prompt
Windows 7/ Vista/ XP
- Click on Windows icon present in the lower left corner of the computer screen.
- Select and click Restart.
- When the screen goes blank, keep tapping F8 key until you see the Advanced Boot Options window.
- With the help of arrow keys on keyboard, Select Safe Mode with Command Prompt from the list and press the Enter Key. The system will then restart to Safe Mode with Command Prompt.
- Click on the username and enter the password (if any).
Windows 10 / Windows 8
- Press and hold the Shift Key and simultaneously click on the windows icon present in the lower left corner of your computer screen.
- While the Shift key is still pressed click on the Power button and then click on Restart.
- Now select Troubleshoot → Advanced options → Startup Settings.
- When the Startup Settings screen appears which is the first screen to appear after restart, select and click on Enable Safe Mode with Command Prompt. The system will then restart to Safe Mode with Command Prompt.
- Click on the username and enter the password.
Once the system starts, ensure to use an account with administrative privilege to access Safe Mode with Command Prompt.
After the user enters admin credentials, Command prompt window is displayed wherein you are entitled to enter the below commands:
- Type the command “sc delete djvu ransomware” in the command prompt and press Enter.
- Type “exit” to exit the command prompt and restart the system in safe mode with command prompt.
STEP B: Restore your system files and settings
Tips to prevent your computer system from getting infected –
- Keeping the Operating System Updated- In order to remain protected and avoid such infections, it is recommended to keep your Operating System updated by enabling the automatic update on your system. The systems with outdated or older versions of Operating System become an easy target for the attackers.
- Resist clicking on spam emails – One of the major techniques used for malware distribution is forwarding spam emails to the user. The system gets infected as soon as the user clicks on the attachment. These mails appear to be genuine, so be aware and resist falling for these tricks.
- Keep an eye on third party installations- It is quite important that you take due care while installing any third party applications for they are major source of such infections. Such malware programs come bundled with the free applications thereby requiring the user to remain cautious.
- Regular periodical backup- In order to keep your data and files safe, it is recommended to take regular back up of all your data and files either on an external drive or cloud.
- Use Anti-Virus Protection- We strongly recommend the use of antivirus protection/internet security in your PC like Sophos and Vipre so that it remains safe.
- Enable the Ad Blocker/Popup Blocker in your browser- Enabling the popup blocker/ ad blocker in your chosen browser will help you to stay protected from annoying adware.