: If it is locked, look for a "hint" file or strings within the archive's header. Common passwords in these types of challenges are often thematic (e.g., magical , rainbow , sparkles ).
: Try to list the contents without extracting: 7z l Unicorns.And.Rainbows.7z Unicorns.And.Rainbows.7z
If you are analyzing this for a lab or competition, here is how to proceed: : If it is locked, look for a