Complete Gudie to Remove CryptoNar Ransomware from PC

Guide to Remove CryptoNar Ransomware

Are you unable to access your system files? Do you find .fully.CryptoNar or .partially.CryptoNar extensions appended to the file names? This indicates that you have fallen in trap of a malicious CryptoNar ransomware, a variant of CryptoJoker ransomware that is known to have raised havoc two years ago.

Ransomware attack is now no longer front-page news and the devastation caused by it can be traced back to middle of 2000. The success of ransomware attacks overtime has encouraged cyber criminals to come up with new versions of this malicious crypto virus and extort users. Ransomware attacks are prominent among enterprises, SMBs (Small and Midsize Business) and individuals alike.

With more than 7600 attacks, ransomware has emerged as new global threat when compared with a total of 6000 combined data breaches for the same time period. It has caused a loss of an alarming $1.6 million.

CryptoNar Ransomware- Threat Behavior

CryptoNar Ransomware, a newly discovered crypto virus distinguishes from its counterparts. Unlike its analogues, CryptoNar Ransomware is configured such that it is capable of encrypting the file partially as well. It uses sophisticated encryption algorithm to do so.

If the file has .txt or .md extension, it encrypts the entire file and appends the filename with .fully.cryptoNar extension.

All other files are partially encrypted with only the first 1,024 bytes ciphered. The names of partially affected files are appended with .partially.cryptoNar extensions

Once done with the encryption, this malware is designed to deliver public/private key pair of the infected files to the attackers for author/system identification to validate the attack.

Victims are informed about the malice via a ransom note in a file called CryptoNar RECOVERY INFORMATION.txt that demands a ransom of $200 in bitcoins to the enclosed address.

The note instructs victim to include their email and personal id in the ‘extra note’ while making the transaction.

Once the payment is made, ideally decryptor key should be delivered to the user but all in vain..

Hence users are recommended not to fall in the trap and instead follow the guidelines given at the end of this article to protect your system against CryptoNar Ransomware.

CryptoNar Ransomware- Spread Techniques

The cybercriminals use various strategies for malware distribution which include –

1. 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.
2. 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.
3. 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.
4. 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 Files:

The CryptoNar virus follows a typical ransomware approach and uses a built-in list of file type extension to identify which files to infect. A strong cipher algorithm is used in the process. The end goal is to swindle victims by persuading them to pay the criminals a decryption fee. The file types targeted by this ransomware include:

• Database
• Videos
• Audios
• Images
• Archives

Furthermore, the typical ransomware runs a command that deprives users of the Shadow Volume copies (automatic and manual copies of computer file). Hence a prominent way to restore OS (operating system) settings is obliterated.

Threat Summary

Name: CryptoNar

Targeted Operating System: Windows

Category: Ransomware

Symptoms: User’s files are encrypted with strong encryption algorithm. The file names of all the infected files are appended with .partially.CryptoNar or .fully.CryptoNar extensions and hence cannot be accessed by the user. A ransom note is dropped on the victim’s system in a file CryptoNar RECOVERY INFORMATION.txt that informs victim about the encryption and demands a ransom of $200.

How to remove CryptoNar Ransomware from the System?

STEP A: Remove the Services installed by CryptoNar ransomware from the system using safe mode with command prompt.

Windows 7/ Vista/ XP

1. Click on Windows icon present in the lower left corner of the computer screen.
2. Select and click Restart.
3. When the screen goes blank, keep tapping F8 key until you see the Advanced Boot Options window.
4. 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.
5. Click on the username and enter the password (if any).

Windows 10 / Windows 8

1. Press and hold the Shift Key and simultaneously click on the windows icon present in the lower left corner of your computer screen.
2. While the Shift key is still pressed click on the Power button and then click on Restart.
3. Now select Troubleshoot → Advanced options → Startup Settings.
4. 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.
5. 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:

1. Type the command “sc delete CryptoNar ransomware” in the command prompt and press Enter.
2. 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

Method 1 using Control Panel

1. Click on the ‘Start’ button on the taskbar. This will open the Start menu.
2. Click on the ‘Control Panel’ button in the Start menu. This will open the control panel window.
3. In the Control Panel window, click on the ‘View by:’ button on the top right. Select the Large Icon option
4. In the control Panel window click on the ‘Recovery Icon’. This will open a window that will ask ‘Restore the computer to an earlier point in time’.
5. Click on the ‘Open system restore’ button. This will open the ‘system restore ’window where you need to click on the Next Button.
6.  Select the restore point that is prior the infiltration of CryptoNar ransomware. After doing that, click Next.
7. This will open the ‘Confirm your restore point’ dialog box. Click on Finish button. This will restore your system to a previous restore point before your system was infected by CryptoNar ransomware.

Method 2 using Command Prompt

1. Type cmd in the search box and click on the command prompt to open the Command Prompt window. box and clicking on it.
2. Once the Command Prompt window shows up, enter cd restore and click Enter. (Ensure that you in the system32 directory of Windows folder in C Drive)
3. Now type rstrui and press Enter again.
4. When a new window shows up, click Next and select your restore point that is prior the infiltration of CryptoNar ransomware. After doing that, click Next.
5. This will open the ‘Confirm your restore point’ dialog box. Click on Finish button. This will restore your system to a previous restore point before your system was infected by CryptoNar ransomware.

Method 3 : Directly type ‘rstrui’ in the search box

1. Type ‘Rstrui’ in the search box present on the task bar. This will open the System restore dialog box.

Continue to follow steps 4 & 5 of Method 2 to restore the System Files and settings.

Tips to prevent your computer system from getting infected –

1. 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.
2. 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.
3. 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.
4. 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.
5. Use Anti-Virus Protection- We strongly recommend the use of antivirus protection/internet security in your PC like Kaspersky Labs Inc and Hitman pro so that it remains safe.
6. 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.