MSE harasses an innocent little program

I have a small video editing program (Machete) that has been running very well since 15 months. All of a sudden MSE decides to harass it throwing the full power of the msmpeng.exe at it using 98% of the CPU for 3 to 4 minutes when I launch that program.
I solved the problem by setting the poor program on the "Excluded files and locations" list of MSE. I am, however, still interested why MSE would all of a sudden turn hostile against that little program. Any theory is welcome.

whs said:

still interested why MSE would all of a sudden turn hostile against that little program. Any theory is welcome.

jealousy maybe

Hallo WHS, i have had a similar thing happen not with MSE and it corrected itself after the next definitons update

Thanks guys for the inputs. I reported the problem to their security group and attached the .exe in question. Let's see what they say - if any.

file injection?