Bwas.7z -

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

Files might be hidden in Alternate Data Streams (ADS) if the archive was sourced from a Windows environment. BWAS.7z

The 7z signature ( 37 7A BC AF 27 1C ) might be slightly altered to prevent standard extraction tools from recognizing it. Depending on the specific challenge version, the "hook"