CLUE 1
Here, a base64 encoded string was given to you: R28gdG8gaHR0cHM6Ly9pbWd1ci5jb20vYS9WemkzVCBhbmQgaGF2ZSBmdW4gY29tcGxldGluZyB0aGUgY2hhbGxlbmdlCg==
Decoding it leads you to a QR code image.
If you try to decode it, you'll get error. Well, the problem with this QR code is that it's white-and-black parts have been inverted.
If you have seen enough QRs, you'll get the problem with this image soon :D . Otherwise, you'll probably end up scratching your head and giving up. :P
