Just had an interesting thing happen. Malwarebytes Pro just blocked WRSA.exe from accessing the snu.webrootcloudav.com site. They have been running together fine for months with no problems. I placed snu.webrootcloudav.com on Malwarebytes "OK" list.
That is the second report of this happening that we have received today. Given what you are describing I would say that it is down to a false positive on the MBAM side of things.
Checking out the site over at Brightcloud yields the following which suggests the FP is probably the issue: