Nemucod Ransomware

Also Known As: Nemucod virus
Distribution: Low
Damage level: Severe

Nemucod ransomware removal instructions

What is .Crypted?

Nemucod is a trojan that downloads additional malware onto victims' computers. Cyber criminals proliferate this software via emails containing attached zipped files. These emails often claim to be legitimate invoices, notices of appearance in court, or other official documents. Computer users commonly fall for these scams and open the attached documents that contain a JavaScript file. The file then downloads the Nemucod trojan onto their systems. Previously, the Nemucod trojan downloaded and installed TeslaCrypt and Locky ransomware on victims' computers, however, it recently started a new campaign whereby it downloads ransomware to encrypt users' data (adding the .crypted extension to compromised files and creating the DECRYPT.txt file on victims' desktops).

The DECRYPT.txt file contains a message stating that files stored on the victim's computer have been encrypted. Files are encrypted using the RSA-1024 encryption algorithm - this means they can only be decrypted using a private key, which is generated during encryption. This key is supposedly stored on remote servers controlled by cyber criminals. The message states that to restore the files, users must pay a ransom of 0.60358 BitCoin (at time of research, equivalent to $252.53). The file also provides step-by-step payment instructions, however, research shows that the statement regarding the encryption algorithm is false. In fact, this ransomware uses the XOR algorithm, Thus, encryption (embedded in the aforementioned executable, which is downloaded by Nemucod trojan) and decryption keys are identical. Therefore, it is possible to use this key to decrypt files without payment. Furthermore, the ransomware does not delete shadow volume copies. Therefore, these copies and 'System Restore' can be used to restore files affected by this ransomware.

Screenshot of a message encouraging users to contact the developers of Crypted ransomware to decrypt their compromised data:

Crypted decrypt instructions

Update 22 April 2016 - Nemucod ransomware now uses 7-zip to encrypt the victim’s files. The ransom amount was lowered from 0.60358 bitcoins to 0.49731 bitcoins. Here’s a screenshot of an updated ransom demanding message:

nemucod (.crypted) ransomware updated ransom demanding message

Update 23 March 2016 - Victims of this ransomware can use a decrypter created by Fabian Wosar from Emsisoft to decrypt their compromised files for free. Download it HERE.

Update 2 July 2017 - Cyber  criminals have updated the ransom demanding message displayed by this ransomware. This variant of Nemucod ransomware doesn't add any new extensions to encrypted files. The appearance of the ransom demanding pop-up:

nemucod ransomware updated variant pop-up

Nemucod ransomware now adds such image as victim's desktop wallpaper:

nemucod ransomware wallpaper

Update July 13, 2017 - Security researcher Fabian Wosar has released a free decrypter for the latest variant of this ransomware. You can download it HERE.

Text presented in the updated ransom demanding message:

ATTENTION!
All your documents, photos, databases and other important personal files were encrypted using a combination of strong RSA-2048 and AES-128 algorithms. The only way to restore your files is to buy decryptor. Please, follow these steps:

1. Create your Bitcoin wallet here: blockchain.info/wallet/new
2. Buy 0.11471 bitcoins here: localbitcoins.com/buy_bitcoins
3. Send 0.11471 bitcoins to this address -
4. Open one of the following links in your browser: -
5. Download and run decryptor to restore your files.
You can ding this instruction in “DECRYPT” file on your desktop.

All ransomware-type malware is very similar - it infiltrates systems via malicious email attachments, infected files distributed via P2P (peer to peer) networks (for example, Torrents), fake software updates, and/or trojans. The only differences are the size of ransom payment and type of algorithm used to encrypt the files. Be attentive when downloading attachments sent from suspicious/unrecognized email addresses. Furthermore, download your desired files from trusted sources. Keeping installed software up-to-date and using a legitimate anti-spyware/anti-virus suite will also help to protect your system. There is no guarantee that your files will ever be decrypted even after paying the ransom and, therefore, you should never attempt to pay or contact the cyber criminals. The ideal solution to crypto ransomware infections is to restore your files from a backup.

Message presented in the DECRYPT.txt text file:

ATTENTION!


All your documents, photos, databases and other important personal files were encrypted using strong RSA-1024 algorithm with a unique key. To restore your files you have to pay 0.60358 BTC (bitcoins).


1. Create Bitcoin wallet here:
https://blockchain.info/wallet/new
2. Buy 0.60358 BTC with cash, using search here:
https://localbitcoins.com/buy_bitcoins
3. Send 0.60358 BTC to this Bitcoin address:
-

4. Open one of the following links in your browser to download decryptor:
-

5. Run decryptor to restore your files.
PLEASE REMEMBER:
- If you do not pay in 3 days YOU LOOSE ALL YOUR FILES.
- Nobody can help you except us.
- It’s useless to reinstall Windows, update antivirus software, etc.
- Your files can be decrypted only after you make payment.
- You can find this manual on your desktop (DECRYPT.txt).

Sample of malicious e-mail spam spreading the Nemucod trojan (which then downloads crypto ransomware on victims' computers):

Spam e-mail spreading Nemucod trojan

Screenshot of files encrypted by this ransomware (.crypted extension):

 crypted ransomware encrypted files

Nemucod ransomware targets these files on victim’s computer:

.3ds .7z .accdb .als .asm .aup .avi .bas .blend .cad .cdr .cpp .cpr .cpt .cs .csv .doc .docx .dsk .dwg .eps .gpg .gz .indd .jpg .kdb .kdbx .lwo .lws .m4v .max .mb .mdb .mdf .mp4 .mpe .mpeg .mpg .mpp .npr .odb .odm .odt .pas .pdf .pgp .php .ppt .pptx .psd .pub .rar .raw .rtf .scad .skp .sldasm .slddrw .sldprt .ssh .sxi .tar .tif .tiff .tsv .u3d .vb .vbproj .vcproj .vdi .veg .vhd .vmdk .wdb .wmf .wmv .xls .xlsx .zip

Crypted ransomware removal:

Quick menu:

Step 1

Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.

Safe Mode with Networking

Video showing how to start Windows 7 in "Safe Mode with Networking":

Windows 8 users: Start Windows 8 is Safe Mode with Networking - Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened "General PC Settings" window, select Advanced startup. Click the "Restart now" button. Your computer will now restart into the "Advanced Startup options menu". Click the "Troubleshoot" button, and then click the "Advanced options" button. In the advanced option screen, click "Startup settings". Click the "Restart" button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.

Windows 8 Safe Mode with networking

Video showing how to start Windows 8 in "Safe Mode with Networking":

Step 2

Log in to the account infected with the Crypted virus. Start your Internet browser and download a legitimate anti-spyware program. Update the anti-spyware software and start a full system scan. Remove all entries detected.


Download remover for Nemucod virus
1) Download and install   2) Run system scan   3) Enjoy your clean computer!

By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Reimage.

If you cannot start your computer in Safe Mode with Networking, try performing a System Restore.

Video showing how to remove ransomware virus using "Safe Mode with Command Prompt" and "System Restore":

1. During your computer start process, press the F8 key on your keyboard multiple times until the Windows Advanced Options menu appears, and then select Safe Mode with Command Prompt from the list and press ENTER.

Boot your computer in Safe Mode with Command Prompt

2. When Command Prompt mode loads, enter the following line: cd restore and press ENTER.

system restore using command prompt type cd restore

3. Next, type this line: rstrui.exe and press ENTER.

system restore using command prompt rstrui.exe

4. In the opened window, click "Next".

restore system files and settings

5. Select one of the available Restore Points and click "Next" (this will restore your computer system to an earlier time and date, prior to the Crypted ransomware virus infiltrating your PC).

select a restore point

6. In the opened window, click "Yes".

run system restore

7. After restoring your computer to a previous date, download and scan your PC with recommended malware removal software to eliminate any remaining Crypted ransomware files.

To restore individual files encrypted by this ransomware, try using Windows Previous Versions feature. This method is only effective if the System Restore function was enabled on an infected operating system. Note that some variants of Crypted are known to remove Shadow Volume Copies of the files, so this method may not work on all computers.

To restore a file, right-click over it, go into Properties, and select the Previous Versions tab. If the relevant file has a Restore Point, select it and click the "Restore" button.

Restoring files encrypted by CryptoDefense

If you cannot start your computer in Safe Mode with Networking (or with Command Prompt), boot your computer using a rescue disk. Some variants of ransomware disable Safe Mode making its removal complicated. For this step, you require access to another computer.

To regain control of the files encrypted by Crypted, you can also try using a program called Shadow Explorer. More information on how to use this program is available here.

shadow explorer screenshot

 To protect your computer from file encrypting ransomware such as this, use reputable antivirus and anti-spyware programs. As an extra protection method, you can use programs called HitmanPro.Alert and Malwarebytes Anti-Ransomware, which artificially implant group policy objects into the registry to block rogue programs such as Crypted ransomware.)

HitmanPro.Alert CryptoGuard - detects encryption of files and neutralises any attempts without need for user intervention:

hitmanproalert ransomware prevention application

Malwarebytes Anti-Ransomware Beta uses advanced proactive technology that monitors ransomware activity and terminates it immediately - before reaching users' files:

malwarebytes anti-ransomware

  • The best way to avoid damage from ransomware infections is to maintain regular up-to-date backups. More information on online backup solutions and data recovery software Here.

Other tools known to remove Crypted ransomware: