Rating:

We are given a sound file, which is Coldplay's song called Flags.

In the end of the file, there are zip archives, which can be extracted with the command binwalk -e flags.wav. One of them is unencrypted and contains the file hint.txt. In the file was the following text:

Assume all characters are lowercase

I found the words in the song at the specified locations in the hint. If there were multiple, I chose the ones, which made the most sense together. The password to the other zip is can_tchaikovsky_talk_to_skeletons_by_a_ouija? and in it is the file flag.txt. The file flag.txt contains the flag UMDCTF-{PY07r_11Y1CH_7CH41K0V5KY}.