Gash Virus Ransomware (.gash File)

What is Gash ransomware?

Infecting the system with Gash ransomware is a case with very dangerous consequences. This virus makes various changes in your system settings, which make your system much harder to use. Of course, besides the settings altering, the malware also encrypts your files, so you cannot open them in any way.

The encryption algorithm used by Gash ransomware is Salsa20. It is typical for all STOP/Djvu ransomware (Gash belongs to that “family”). Decrypting tools allow you to get your files back without payment, but the things also depend on random. If your files are ciphered with the offline key - you have a big chance of getting your files back. However, the online encryption key usually means that decryption is impossible.

The best way to deal with ransomware attacks is to prevent them. Usually, Gash ransomware is spread inside the programs you get on dubious sites. Although these apps are free, they must be purchased on the official website. Other programs are designed for some outlaw things - cheating, for example, or Windows activation. While making the program usable without any payments, hackers are free to add any malware into this program - depending on who paid the most.

Encryption process

The Gash 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 - ".gash". 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 Gash 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 .gash Files?

Indicators of Compromise(IOC)

File Name	MD5	File Size
📜 SAMPLE.EXE	1d4aa5d096a6d1edd9218f200d870618	840192
📜 SAMPLE.EXE	b1e675fa97bb5304e0299631a4b31866	845312
📜 SAMPLE.EXE	60bce77ac3b293a0b6499116dbbd40d4	840704
📜 SAMPLE.EXE	f37ee31206675324ab26cebda09ce213	840192
📜 SAMPLE.EXE	712a61ae2ddf17f0e35543284b38ecb5	840704
📜 SAMPLE.EXE	263a1d2ec85ab0b6468445a61b276a3c	840192
📜 SAMPLE.EXE	6c66b3984045971ccc09cd8ea4e44d26	844800
📜 SAMPLE.EXE	a5e7720550a0973a62348ec0d2385027	840704
📜 SAMPLE.EXE	15960ee1d745b35af86869d19099def2	839680
📜 SAMPLE.EXE	d3397d46b16cebcb81453722bf5501b3	840704