NMAP alerts

[bdushok () luzerne edu]

I've been noticing a few PC's on our network generating large numbers of 
NMAP alerts (icmp ping nmap).   It seems to be caused by "CNet Download 
Manager".  I found this app loaded on two PCs generating the alert and, 
after removing it, the alerts appear to have disappeared.  Has anyone else 
encountered a similar problem?

Thanks,
Bob