Contact needed for CERFnet?

Sorry to pester on this. I've been working with a couple of clients who
had connectivity issues. All more or less had the same problem, the
dreaded viruses/worms/etc* issues. I was forwarded a call from tech
support for a 'favored' customer and was told to get them up no matter
what. Making a long story short, their machine had their dialup settings
changed somehow to call a number (cust is contacting telco to see what
number was dialed) and connect to the following address 12.129.205.220

~> whois -h whois.arin.net 12.129.205.220
AT&T WorldNet Services ATT (NET-12-0-0-0-1)
                                  12.0.0.0 - 12.255.255.255
CERFnet ATTENS-LAX1-1 (NET-12-129-192-0-1)
                                  12.129.192.0 - 12.129.255.255

Nothing but a webpage that states "Place Holder" is located there.
Normally I wouldn't even care, but I recall someone else mentioning this
address earlier in the day. So I called and confirmed there have been a
few hijacked connections going to this machine. Anyone know how a contact
for this range? Also has anyone heard of anything similar?

Thanks and apologies if inappropriate