One of the most dangerous things in computer malware is the Zero Day Exploit where an error in a program is used by the bad guys before it can the hole in software can be fixed.
A particularly irritating zero day exploit is the TIFF bug in Windows systems where users using Microsoft products can be fooled into opening what appears to be an image file but what turns out to be something more malicious.
Even more irritating with this bug is that Microsoft aren’t going to fix the problem in Windows XP systems until January’s patch Tuesday which means many people will be susceptible to this problem for nearly two months.
Zero day exploits are a good reason why every computer user needs to have an up to date virus checker and to take basic precautions before surfing the web or downloading email.
For Windows users it might be worthwhile taking extra care with email attachments for the next few weeks.