Where should I store these variables?

[Antivirus]

Datastore is definitely the way to go. Have yur script run as a scheduled task once per day, storing the info in the datastore, then using a plugin in forumhome you can simply acces the data using $vbulletin->mydatastorefield. The article Dismounted mentions above is excellent. I think you can find it by searching the articles forum for the term cache or serialize