Bwas.7z -

Depending on the specific challenge version, the "hook" is usually one of the following:

The 7z signature ( 37 7A BC AF 27 1C ) might be slightly altered to prevent standard extraction tools from recognizing it. BWAS.7z

Running file BWAS.7z confirms it is a 7-Zip archive data file. Depending on the specific challenge version, the "hook"

If the archive prompted for a password, use or hashcat : Extract the hash: 7z2john BWAS.7z > bwas.hash Depending on the specific challenge version