If suddenly the realization hits that it’s been more than a week since you updated your virus-signature file, you better scan your computer for viruses immediately — particularly if you’re the active type (lots of e-mail, file sharing, file swapping, opening mail from strangers, and other such cyber-exuberance).
The more time that has gone by since your last signature update, the more important it is that you do a whole-system scan. For instance, if two weeks has elapsed since your last update, then any virus less than two weeks old could have entered your computer unhindered. Here’s why that’s a cause for concern:
- The viruses you’re likeliest to catch are new; your antivirus software doesn’t yet know how to detect them.
- New viruses are joining the online feeding frenzy every day. If you haven’t update your defenses for two weeks, who knows how many viruses looked at your computer, went yum, yum, and moved right in?