I've just spotted in .bash_history file lines below:grep -iHlnr 'filesman' *2> /dev/nullgrep -iHlnr 'eval.*base64_decode' *2> /dev/nullFrom Google I know that is something like 'malware finding command'. May somebody explain what does it exactly do? (Iknow what is grep for, but that syntax isn't clear to me).
Explain Malware-finding function in bash
grep;malware
The commands you posted do nothing useful they run grep on files whose name ends with 2, and recursively in directories whose name ends with 2. There's a missing space after * (the space after > is permitted but not useful and more confusing than anything):grep -iHlnr 'filesman' * 2>/dev/nullgrep -iHlnr 'eval.*base64_decode' * 2>/dev/nullThis searches for files containing filesman, or containing eval followed by base64_decode on the same line, in the current directory and its subdirectories recursively. The search is case-insensitive. Look at the manual of grep for the exact meaning of each option.Calling that malware finding is a gross exaggeration. It's probably looking for PHP malware, but it might return some legitimate files as well and it only finds a few specific malwares.