Fckrgzip -

If you encountered this file in a server directory or a repository, it is often a sign of a "web shell" or a custom compression script used to exfiltrate data. 2. Experimental or Personal Repositories

Includes a 10-byte header containing a "magic number" ( 1f 8b ), a compression method, and timestamps. fckrgzip

Uses the DEFLATE algorithm (a combination of LZ77 and Huffman coding). If you encountered this file in a server