The download wasn't the message. It was the warning.

The file arrived without a name. Just a string of gibberish: nwdz andr aydj mhjbt sl tlb bbzazha...

I looked up. The webcam light was green.

"This file is encrypted. Enter passphrase."

It looks like the text you provided ("Download- nwdz andr aydj mhjbt sl tlb bbzazha...") is scrambled — possibly a cipher, keyboard smash, or encoded message. The phrase "nwdz andr aydj" resembles a simple shift cipher (like Caesar cipher) or a keyboard layout shift (e.g., typing with hands shifted one key on a QWERTY keyboard).