Bach_guitar.rar

Check for DTMF tones (phone keypad sounds) that might represent a code. The flag is usually hidden in one of three ways:

Looking for a in the archive (using 7z l -slt Bach_Guitar.rar ).

Use strings to look for readable text at the end of the file. Inspect the LSB (Least Significant Bit) using zsteg . Open the file in Audacity . Bach_Guitar.rar

Text appearing as "waves" in the audio spectrum.

Attempt to extract the archive. Many versions of this challenge are password-protected. Check for DTMF tones (phone keypad sounds) that

Data hidden after the "End of File" marker (EOF), viewable in a Hex editor.

A text file named flag.txt extracted from the image. Bach_Guitar.rar

Checking the of the .rar file itself (using exiftool ).