Found an interesting article in the latest Windows Secrets news letter about malware hijacking flash banner ads.
There was another in the paid version (I only get the Free version) about Firewalls.
Flash ads bearing malware plague popular sites
A Flash-based advertisement that appeared last week on the USA Today site downloaded malicious code to users’ computers, generating erroneous warnings of a malware infestation and offering a phony solution. The Flash vulnerability is so widespread that such “malvertisements” may be present on thousands of sites, but there are measures you can take to reduce your exposure.
This is from the paid version
• The best — and worst — personal firewalls
UncleDoug