Wwhu Virus Ransomware (.wwhu File)

What is Wwhu ransomware?

Wwhu ransomware belongs to the STOP/Djvu ransomware family. This malware family is usually targeted at individuals. Besides the statistics, this targeting can also be figured out through the specific distribution methods and actions this malware does after the injection. It encrypts the files with a robust cipher - Salsa20, which is impossible to “hack”. All decryption keys are kept on the remote server, controlled by cybercriminals.

This malware makes some changes to your system configuration. One of the most significant is stopping Microsoft Defender and preventing the anti-malware software installation files from launching. These changes are done through the Group Policies - a particular interface in Windows for interaction with deep system settings.

Wwhu ransomware is usually spread through the dubious sites that offer the programs for free. Usually, you need to buy these programs, but these web pages offer a very tempting offer - get it without any payment. They make the programs usable without any licensing by hacking their source code. These crooks can easily add any virus at the moment of source code editing. Which one? Depending on how much they paid for the certain malware.

Other sources of Wwhu ransomware are so-called hack tools. Apps like keygens, Windows activation tools, cheat engines, and so on are perfect carriers for any malware. Using them, you are risking not only getting infected with the Wwhu virus but also being fined for unlicensed software usage by local authorities.

Encryption process

The Wwhu ransomware uses the Salsa20 encryption algorithm. That is not the strongest method, but it still provides an overwhelming amount of possible decryption keys. To brute force the 78-digit number of keys, you need 3.5 unvigintillion years (1*10^65), even if you use the most powerful regular PC. Quantum computers can show a bit better results, but it is still too slow to get your files back while you are alive.

The exact algorithm of encryption is next: malware scans each folder for the files it is able to encrypt. Then, when it finds the target, it makes a copy of your file, removes the original one, encrypts the copy and leaves it instead of the removed original. Such a procedure is done to prevent the situation when you have already opened the file, so ransomware is not able to read it because of the Windows restrictions. To each encrypted copy, the virus adds the specific extension - ".wwhu". Then, ransomware creates a _readme.txt file in the folder where the encrypted file is located, and goes to the next folder.

Such an encryption method can be exploited for file recovery. Since the original file is deleted, you may try to recover it using the file recovery tools. The less time is passed - the bigger the chance to get your files back, so hurry up!

Another specific moment that can help you to use the files even after the encryption is the fact that Wwhu ransomware encrypts only the first 150KB of each file. Hence, you can try to run a big file, such as video or music, without the encryption. Similar feature also works with other ransomware families - Dharma, Conti and Makop encrypt the same 150KB.

Ransom note: _readme.txt

Ransom note is the same for the whole ransomware family. In fact, it is one of the main signs of to which family the certain ransomware belongs. Here is the typical note for STOP/Djvu family:

External Links:

🔗 HowToFix.Guide: How To Decrypt .wwhu Files?

Indicators of Compromise(IOC)

File Name	MD5	File Size
📜 SAMPLE.EXE	46bfcb0bea42b9ba083113bd6a045646	227840
📜 SAMPLE.EXE	e78ccf1b9d072d36b47d1424e76bc4d1	253440
📜 SAMPLE.EXE	4a53c55f868be3806cc199adbb8a6bbe	227840
📜 SAMPLE.EXE	904630c40e260cef6eb6dd6cf98ba287	251392
📜 SAMPLE.EXE	d0a04db69d0ecbb5255561d4805d291f	269312
📜 SAMPLE.EXE	28eb23eeb88c720f74db451c54dcf765	141031
📜 SAMPLE.EXE	22e2561167ada390a9d0d58bcf899657	756224
📜 SAMPLE.EXE	b1bffa4b91e0e0748caaf741470e3fa2	244224
📜 SAMPLE.EXE	46e078164e91be826e2ed8e8da452904	1273856
📜 SAMPLE.EXE	04958a3373b0a619bdd754941f956561	304640