Random BSOD while browsing internet
BitDefender is nothing special. mwac.sys causes BSODs anywhere.
A tiny documentation can be found here:
In that very thread, the suggested action apparently worked.
The storage and network filters of any third party antivirus can cause BSODs. Neither MBAM nor BitDefender is any special. For a regular antivirus, it may be shifted to an alternative; but MBAM has no alternative. So a clean install of the said program is the most feasible first step.
As far as the first step is not failing, it is better to not think for the second step. Because the BSODs are not universal, failure at the first step is not universal; and success at the second step is also not universal.
That is why I posted that my suggestion may work, or may not. Let us see where it goes.