My Esxi4 is reported as participating in NTP Distributed Denial of Service (DDoS) attack

Hello,

I received a report that my Esxi 4.1 host is participating in a NTP Distributed Denial of Service attack. 

I posses limited Vmware skill set and this is what I have done so far:

1. Stopped the NTP Daemon service - see attached screen shot.
2. Ran "#esxcfg-firewall --closePort 123,UPD,in"

However, I am still getting reports that my host is participating in the NTP attack.  Did I miss anything else?

Thanks in advance for any help