055

🔎 Solution

The challenge provides the following string:

MCZJ/CJ[[J].7¿?;(?9!?-/<;¿:=(=6!?-X
K: wtf

It looks like random characters along with a key. After testing several decoding methods, it turns out this was encoded using XOR.

Using CyberChef to decode the string produced:

BLUE LETTER!8°04'06.0" 34°52'29.0"W

This appears to be a set of GPS coordinates, although the latitude is missing a directional indicator. Testing the coordinate with S gives:

8°04'06.0"S 34°52'29.0"W

Checking this location reveals graffiti in the area with a blue word: "CAP". That turned out to be the flag.

HMV{CAP}