As long as the Trojan is moderately advanced, there is nothing to stop it (currently, mouse and cat).

The only thing one can do is to detect signs of its activities, just routine.

When the least unexpected day one detect the signs, one notify to the work circle that the machine has been compromised for to rescind our permissions, it is tried to find out how entered and get an idea of the time during which the data leak has occurred, as anything relevant you did in that machine is on some public page on internet.