Just in time for spring, Microsoft has been busy tending to a new swarm of bugs, including a critical hole in Windows Vista and XP that could expose you to an early-season bite without your doing anything other than being online.

In an attack, a cracker could broadcast rogue TCP/IP packets to a range of addresses on the Internet, possibly including your PCs. Sounds all too common, right? These rogue packets, however, are designed to trick their way past Windows' security and hijack your PC, making your machine part of a botnet for sending out spam - or worse, a self-copying worm.

So far, no attacks have occurred. But proof-of-concept code is floating around, so don't put off applying the patch. If you've enabled automatic updates, Microsoft will push the patch to you. Otherwise, you can grab it from Microsoft and install it yourself.

End Excel Zero-Day Attacks

Microsoft is scrambling to plug a hole in Excel that's already under a zero-day attack (the name means the exploit was out before a patch was). Though Microsoft characterises the attack as "limited," the problem is serious.

The vulnerability is in Excel 2003 Service Pack 2 for Windows (and earlier), and in Excel 2004 for Mac. Feeling smug because you don't have Excel? Don't be. Even Excel Viewer 2003 is at risk. You're fine if you use Excel 2007 for Windows or Excel 2008 for Mac, or if you've installed SP3 on Excel 2003 for Windows.

The attacks can hit you whether you open a poisoned email attachment or click on a tainted Excel file on a website.

The lesson: Always question file attachments, especially if they seem unusual somehow. "Were you expecting it? Maybe pick up the phone and call that person and ask if they sent it," says Alfred Huger, vice president of engineering for Symantec Security Response.

Firefox Plug-Ins Pose Risk

Meanwhile, Mozilla has plugged a hole that could enable Firefox to leak information like a sieve, owing to a flaw in "flat packed" browser add-ons. Such add-ons - and there are a lot of them at risk - are the kind that are not stored as '.jar' files. The bug allows a malicious program to hack into directories on your computer, looking for commonly named files that may contain information such as browser cookies holding user names and passwords.

If you have Firefox's automatic updates on, you will be prompted to update. Otherwise, head to getfirefox.com to download Firefox version 2.0.0.12.

When Picture Frames Attack

Digital picture frames were hot gift items this past Christmas. Unfortunately, some frames sold by Best Buy were infected with a Trojan horse. The infected units are all 10.4-inch versions, model number NS-DPF10A under Best Buy's Insignia store brand. If you don't have anti-virus software and you've already plugged the frame into your PC, the malware could have spread. See "Best Buy Sold Infected Digital Picture Frames" for more details and a link to assistance.
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