Decrypt and remove CrypMIC/CryptMIC ransomware

Find out how to get around the data encryption by CrypMIC / CryptMIC ransomware, learn what other infection it resembles and get the attack workflow details.

When the CrypMIC ransomware campaign broke out in late July 2016, it instantly drew the attention of security experts. Also dubbed CryptMIC, this computer threat bears a resemblance to an older file-encrypting Trojan known as CryptXXX. A striking similarity can be observed in the distribution technique, the contents and design of ransom instructions, as well as the ransom size. Both of these offending programs are being deposited on PCs via the Neutrino exploit kit. The amount of money that victims are required to pay for recovering their personal data is 1.2 Bitcoins in either case, and it becomes twice as big if the user fails to submit it during 100 hours since the attack commenced. Meanwhile, the attributes that aren’t shared between these samples include the encryption algorithm applied, the names of recovery notes, and the way CrypMIC handles filenames of encoded items.

More specifically, CryptMIC leverages the symmetric AES-256 algorithm to lock one’s data, although it deceptively states in the warning messages that the cipher is asymmetric RSA-4096. The difference being drastic, both AES and RSA are virtually uncrackable if deployed properly. One way or another, the files locked by this ransomware cannot be completely restored without the master key owned by the attackers. Regarding the documents that contain restoration directions, they are named Readme.html, Readme.txt and Readme.bmp. The corresponding icons are added to the infected computer’s desktop and all folders with corrupted files. The main message therein is as follows, “All of your files were protected by a strong encryption with RSA4096,” which is partly a bluff as far as the actual cryptosystem is concerned.

As opposed to CryptXXX, CrypMIC does not alter the names of encrypted entries. This means that no specific extension is appended, nor are the filenames scrambled either. This approach makes it problematic for a victim to figure out what exactly has been affected on the hard drive and network shares – the only way to find out is by trying to open a specific item, which will return an error. In order to get the data back to its accessible state, the infected user is supposed to install Tor Browser and visit one of the two .onion pages listed in the Readme.html (.txt, .bmp) files. The site titled “Decryption service” then tells the person to enter their personal identification code, which is also provided in the ransom notes. It is a string consisting of 4 blocks of 8 hexadecimal characters separated by colons.

Having thus logged into the service, the victim will see how much time they have left before the ransom goes from 1.2 BTC to 2.4 BTC, their operating system and IP address details, as well as the information on the Bitcoin wallet that the digital cash should be sent to. Interestingly enough, CrypMIC claims to upsell a product called the “Microsoft decryptor”, which is the alleged restoration tool. Whereas there is currently no free decrypt solution for files skewed by this threat, a couple of techniques may come in handy to revive some information.

CrypMIC / CryptMIC ransomware automated removal and data recovery

Owing to an up-to-date database of malware signatures and intelligent behavioral detection, the recommended software can quickly locate the infection, eradicate it and remediate all harmful changes. So go ahead and do the following:

1. Download and install the antimalware tool. Open the solution and have it check your PC for PUPs and other types of malicious software by clicking the Start Computer Scan button

Download CrypMIC / CryptMIC virus remover

2. Rest assured the scan report will list all items that may harm your operating system. Select the detected entries and click Fix Threats to get the troubleshooting completed.

Data recovery toolkit to the rescue

Some strains of ransomware are known to delete the original files after the encryption routine has been completed. As hostile as this activity appears, it can play into your hands. There are applications designed to revive the information that was obliterated because of malfunctioning hardware or due to accidental removal. The tool called Stellar Data Recovery features this type of a capability and therefore it can be applied in ransom attack scenarios to at least get the most important files back. So use the app to get an idea of what data can be restored and let it do the recovery job. Here is a step-by-step walkthrough:

1. Download and install Stellar Data Recovery.

Download Stellar Data Recovery

2. Open the application, select the types of recoverable files to look for, and click Next.

3. Choose the areas you want the tool to recover from and click the Scan button.

4. Having scanned the specified locations, the program will display a notification about the total amount of recoverable data. Close the dialog and click the Recover button. This will hopefully help you get some of your valuable files back.

Ransomware Prevention Tips

To avoid CrypMIC / CryptMIC ransomware and other file-encrypting infections in the future, follow several simple recommendations:

These techniques are certainly not a cure-all, but they will add an extra layer of ransomware protection to your security setup.

Revise your security status

Post-factum assessment of the accuracy component in malware removal scenarios is a great habit that prevents the comeback of harmful code or replication of its unattended fractions. Make sure you are good to go by running an additional safety checkup. Another benefit of using the antimalware tool is that it will keep ransomware threats from intruding on your computer further on.

Download CrypMIC / CryptMIC ransomware removal tool