Crypt.rar -

: A popular file encryption software that frequently updates its release notes for Windows, macOS, and mobile. 3. Password Recovery (Cracking)

There are legitimate utilities and libraries used to "crypt" (encrypt) RAR files:

: Recent variants of this ransomware append extensions like .rar to victims' files (e.g., image.jpg.[ID].rar ) and leave a ransom note named Read.txt . crypt.rar

Are you trying to for a RAR file, or are you concerned your computer has been infected with ransomware ? To crypt, or to mine – that is the question - Securelist

: Professionals use Hashcat or John the Ripper to perform brute-force or dictionary attacks on encrypted archives. : A popular file encryption software that frequently

: This malware is known for appending the .crypt extension to files.

If you are trying to "look into" an encrypted RAR file you cannot open: Are you trying to for a RAR file,

: Tools like Advanced Archive Password Recovery from Elcomsoft are designed specifically for this purpose.