In this challenge, we were given a file which according to the hint was supposed to be a batch file. But obviously it was obfuscated. Our task was to de-obfuscate the script from which we got a certificate which upon decoding led to an exe file. The exe file had the flag AES encrypted inside it, which could be decrypted to get the flag.
[Read the full writeup](https://medium.com/@ReversedEyes/dotbat-writeup-h-ctivitycon-2021-10f82642d557)