Shortly after installing Bitdefender Total Security my backup software (Macrium Reflect) has had random failures during SMB connection setup. This is happening on only 1 of 5 computers. I installed Bitdefender about 2 months ago and the problem started 4 days later. I can sometimes go 3 days without trouble so that 4 days could be insignificant, Or this could all be coincidental.
I've added the Reflect library as an exception in Bitdefender, but I think the SMB setup happens in Windows code so I doubt the exception will do anything.