Some of the antivirus software that is on the market will block a few of these threats effectively but Malwarebytes is one that is able to take on all of the bad guys.
If this happens to you it can sully the reputation of your web site – the people who come to visit your web site do not know that it was not you serving the ads.
Klez wasn’t as damaging as some of the other notorious worms I’ve written about before but it is still active today, albeit to a far lesser degree than in 2002.
Security failures happen, both on home and work networks, but if the company gives a good faith effort to keep your data safe, then there is not much blame to go around.