It's either seeing something or the time between scans has been messed with. I'm leaning toward the time between scans has been messed with.
It would not hurt to do a deep virus scan. ComboFix is a very good romp and stomp, take no prisoners type of scanner. ComboFix Download
Combofix has gotten better over the years, so I cannot disagree with Setishock. However, it should be made a note of that we are not responsible for anything negitive that comes out of our advice.
You may wish to check your scan settings for MBAM though, because that still doesnt seem right, even with a serious infection. It really should not react that way.