Multiple instances of Excel taking up all of CPU

Lately, I have been having issues where multiple instances of Excel are consuming all of my CPUs. I believe it may be caused by using the Lunchbox Excel Reader components, as it doesn’t seem to happen unless I have Rhino/Grasshopper open with definitions that use multiple Excel Reader components…

Has anyone else experienced this? It seems like a resource leak of some sort, and it looks like a virus, but I am not able to figure out how to stop this from happening. The issue goes away after restarting my computer.