In this challenge, we have a long text file.We can see that it ends with VldwR1MxSXhVbk5YYlhSWFRWZFNSMVV5ZUdGV01rcFpZVVpvV0Zac2NGaGFSVnBYVjFkR1IxTnRiRk5YUlVwVVZtMHhNRlV4Um5KUFZrcFJWa1JCT1E9PQ==It looks like base64!I decoded it, but again, the content was base64 encoded.so I created a simple python script that recursively decodes base64:
```#! /usr/bin/env python3import base64with open('ciphertext', 'r') as content:	text = content.read()	while 1:		try:			text = base64.b64decode(text)		except:			print(text)			break```
 and our flag is:
'UMDCTF-{b@se64_15_my_f@v0r1t3_b@s3}'