Today we give away decorations for your Christmas tree. But be careful and do not break it.
Attached to that we receive a STL file named Triangulation. This file is a 3D model.
Opening this in blender and peeling the shell. Showed that it contains another shell. Peeling this again revealed an AZTEC code. Tweaking the thiccness got me the following model, which I was able to scan.
The flag is HV19{Cr4ck_Th3_B411!}.