Android keeps downloading an unknown file

about a few days ago i discovered an unknown file in my downloads on my phone (Samsung Galaxy S21FE). It could not open it on my phone so i just transfered it onto my pc to open it. It contains somethig that looks like Hex-Values "91e1f39[...]092abb0e2333b8f2e" (in the [...] are more of this). I doesnt have any extension, or information where it comes from. It just has a name "testing". When i delete it, it randomly appears on my phone a few days later... Do you have any idea what this could be? Thanks