Pepe is alpha tier
Author: Degenerat3
ctf_pepe.png
exiftool shows an image description:
gh:cyberme69420/hdpepe
When checking out that github repo you can find source code to embed a file into the alpha channel of an image. The file to be embedded is first encoded to base64 and then 255 - value is applied for each character. In the repo is also an examiner script that you can easily modify to perform chr(255 - alpha value) for at least the first 40 characters and you get the base64 string UklUU0VDe00zTTNTX0NBTl9CM19NNExJQ0lPVVN9 and after decoding the flag.
flag: RITSEC{M3M3S_CAN_B3_M4LICIOUS}