I know that I've mention this in the past, and I'm not advocating running no antivirus software, but it's good to remember that you're using high-privileged software to load untrusted data. While mistakes can happen in any reasonably complex software, some companies are more complacent than others, and some design choices fail to respect the trust you have in them. Symantec, as far as I know, has one of the better reputations of security companies, but this flaw is terrible.
Basically, to detect malware that has been obfuscated by executable compression, antivirus software unpacks it themselves and looks. Symantec's solution runs in the kernel, allowing any malware that targets it to have kernel permissions. They were also using “at least” seven-year-old forks of open source libraries. Well… crap.
The bugs have been privately disclosed to Symantec, and fixed before Google went public. If you have any Symantec, or their consumer brand, Norton, software, then make sure it's up to date. Consumer software will have the fix pushed through LiveUpdate, but some some products, like Symantec Endpoint Protection and Symantec Protection for SharePoint Servers might require administrator action.