Pokerstars are very strict regarding the software that they allow to be installed on the machine. I remember in the beginning that i had installed some kind of
equity calculator and while playing i received message from pokerstars client that there is problem and they sent me email with details. At this time program was not even running. It was just installed but obviously pokerstars client scans quite aggressively your computer looking for suspicious things.
Finally it was all well as they just explained me to read the FAQ with permitted and forbidden software and confirm via mail that i will not do that again. They did not freeze my account or punish me in any other way but the point is that they are definitely looking what you are doing on your machine.