PcClient JM is a fake worm application. A variety of renegade anti-spyware applications and Trojan horses will create phony security alerts about PcClient JM infection, but all of this is geared at tricking the user into purchasing the spyware remover applications. PcClient JM has been known to slow down the system processes of a computer and may result in critical system errors and even a system crash. It is highly recommended that PcClient JM be removed from any system as soon as it is detected.