Before connecting to the Internet             (continued)...


1) Disable nonessential services.
2) Download and install software patches as needed.

Verify the md5 checksum, or PGP signature when possible, of any downloaded patches with a utility like md5(1) or md5sum(1). 

Don't use a file whose signature doesn't match its contents!

3) Connect the new computer behind a network (hardware-based) firewall or firewall router.