While Microsoft did shut it down in 2006, there are sites that have downloads for the updates released by Microsoft. Updates such as "Service Pack 2.1a" are available from many download sites. However these are unofficial and are not always recommended, use at your own risk.
I would not run 98 for anything online now, there are way too many new exploits that will take full advantage of old outdated systems.. Get at least XP with a current anti-virus software.