A "hash" is a "digital fingerprint" of a file that is astronomically improbable to duplicate with other content by accident, and nearly impossible to duplicate intentionally. Therefore, it is often used as a "shorthand" to identify a file.
Calculate the SHA256 sum of TheZeal0t's cryptoware program, and its decryptor program. Enter the two hashes as the flag, separated by a pipe symbol, with the cryptoware's hash first, followed by the decryptor program's hash. Example:
This challenge was pretty straightforward, download the files, calculate the SHA256 hashes and submit the flag:
$ shasum -a256 zealotcrypt-02* 969102c7feb6003624c4caf0e00fa9a60d96bc503ef0beb71ed4af68ba1fc047 zealotcrypt-02-decrypt.bin 5a54fb61f7b1a9b1b7405602388add7e3323890bc74952a62803ffb1a535338b zealotcrypt-02.bin
The accepted flag was,