Weird issue; This is a Korea Net (KORNIC) network that Facebook.com was resolving to on Windows Server 2003 DNS Server Cache. Cleared DNS Server cache, dumped workstation cache (ipconfig /flushdns && ipconfig /registerdns) and it’s resolving properly now.
Lookup against local DNS server:
nslookup www.facebook.com
Server: mydomain.local
Address: 10.3.0.254
Non-authoritative answer:
Name: www.facebook.com
Address: [...]