In the world of comic books, every bad guy is an evil genius. On the Web, hackers, spammers, and phishers may be evil, but they're not required to be geniuses. They can make a healthy living just by exploiting known security holes that many users haven't bothered to patch. Or by relying on the propensity of millions of people to do things they've been told over and over not to do.

The silver lining is that you don't have to be a genius to avoid these common attacks either. Implement a few simple fixes, and you'll avoid most of the bad stuff out there.

Fix 1: Patch Over the Software Bull's-Eye

Have you turned off automatic updates for Windows and other programs on the rationale that "if it ain't broke, don't fix it?" Then consider this: Your programs may be very, very broken, and you don't know it. The days of big splashy viruses that announce themselves to PC users are over. The modern cybercriminal prefers to invisibly take control of your PC, and unpatched software gives them the perfect opportunity to do so.

Today, a hijacked Web page--modern digital crooks' attack of choice--will launch a bevy of probes against your PC in search of just one unpatched vulnerability that a probe can exploit. If it finds one, better hope your antivirus program catches the ensuing attack. Otherwise you likely won't even notice anything amiss as it infects your system.

Luckily, you can completely block the majority of Web-based exploits by keeping all your programs--not just the operating system or your browsers--up-to-date. Attack sites ferret out holes in seemingly innocuous applications such as QuickTime and WinZip as well as in Windows and Internet Explorer. So turn on automatic update features for any software that offers the service--it's your quickest and easiest option for getting patches.

Fix 2: Find the Other Holes

If every program used easy automatic updates--and we were all smart enough to use them--the thriving malware business would take a serious hit. Until then, a free and easy security app from Secunia can help save the day.

The Secunia Personal Software Inspector, available as a free download, scans your installed software to let you know which out-of-date programs might be making your PC unsafe. But it doesn't stop there--for each old program it finds, it offers quick and easy action buttons such as one labeled Download Solution, which retrieves the latest software patch without you even having to open a browser.

The program also gives you links to the software vendor's site as well as Secunia's full report about the vulnerability on your system. You can choose to block future warnings about a particular program (but you should, of course, be careful before doing so).

Secunia PSI isn't perfect, and doesn't always make it easy to update unsafe program components. But for most apps it provides a quick--and very important--fix.

Fix 3: Let the Latest Browsers Fight for