If look to password cracking competitions:
most used software are:
Use zip/rar. With rar you can use password protection.
Along with content provide these files:
Old .nfo use code page 437. New .nfo file use ISO-8859-1/ISO-8859-15 or Unicode UTF-8 characters.
Internet shortcut file. Content like this:
FILE_ID stands for "file identification". DIZ stands for Description In Zipfile.
A crack intro, also known as a cracktro, loader, or just intro, is a small introduction sequence added to cracked software, designed to inform the user of which "cracking crew" or individual cracker was responsible for removing the software's copy protection and distributing the crack.