How to Pronounce GUF

Steps

Import the GIF file into GIMP using convert each frame into layers

Go through each frame and recreate the full QR codes

Scan each QR code and recognise that 6 and 8 look like Base64

FGVDVEZ7YU1

fMV9oYVhYMHJfbjB3p30=

Combining them together FGVDVEZ7YU1fMV9oYVhYMHJfbjB3p30= then doing base64 decode gives

DUCTF{aM_1_haXX0r_n0w}

Flag

DUCTF{aM_1_haXX0r_n0w}