from my limit german...
it seems its a file used when bit defender is updated. Basically its a log file that is created/written when it updates. From what i gather, it can be safely deleted, and it will automatically be recreated next tiem bitdefender downloads the next update..
I guess just delete the update log.. or move it to the bit defender program files. And next time you go to update bitdefender, move the log back to your desktop
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