No internet connection due to invalid DNS (64.120.141.162)

Who/Where: 
Few workstations in UPM system, particularly in the VLAN of CAD
When: 
Wednesday, October 24, 2012 - 10:00 to Thursday, October 25, 2012 - 10:00
Why: 
Possible hacking attempt (still waiting for a report from ASTI)
Account: 

After using online ip-lookup for 64.120.141.162, the IP address is owned by Network Operations Center Inc.

NetRange: 64.120.128.0 - 64.120.255.255
CIDR: 64.120.128.0/17
OriginAS: AS21788
NetName: HOSTNOC-5BLK
NetHandle: NET-64-120-128-0-1
Parent: NET-64-0-0-0-0
NetType: Direct Allocation
RegDate: 2009-04-27
Updated: 2012-03-02
Ref: http://whois.arin.net/rest/net/NET-64-120-128-0-1

OrgName: Network Operations Center Inc.
OrgId: NOC
Address: PO Box 591
City: Scranton
StateProv: PA
PostalCode: 18501-0591
Country: US
RegDate: 2001-04-04
Updated: 2011-09-24
Comment: Abuse Dept: abuse@hostnoc.net
Ref: http://whois.arin.net/rest/org/NOC

ReferralServer: rwhois://rwhois.hostnoc.net:4321

OrgAbuseHandle: SMA4-ARIN
OrgAbuseName: Arcus, S. Matthew
OrgAbusePhone: +1-570-343-2200
OrgAbuseEmail: nic@hostnoc.net
OrgAbuseRef: http://whois.arin.net/rest/poc/SMA4-ARIN

OrgTechHandle: SMA4-ARIN
OrgTechName: Arcus, S. Matthew
OrgTechPhone: +1-570-343-2200
OrgTechEmail: nic@hostnoc.net
OrgTechRef: http://whois.arin.net/rest/poc/SMA4-ARIN

RAbuseHandle: SMA4-ARIN
RAbuseName: Arcus, S. Matthew
RAbusePhone: +1-570-343-2200
RAbuseEmail: nic@hostnoc.net
RAbuseRef: http://whois.arin.net/rest/poc/SMA4-ARIN

RNOCHandle: SMA4-ARIN
RNOCName: Arcus, S. Matthew
RNOCPhone: +1-570-343-2200
RNOCEmail: nic@hostnoc.net
RNOCRef: http://whois.arin.net/rest/poc/SMA4-ARIN

RTechHandle: SMA4-ARIN
RTechName: Arcus, S. Matthew
RTechPhone: +1-570-343-2200
RTechEmail: nic@hostnoc.net
RTechRef: http://whois.arin.net/rest/poc/SMA4-ARIN