Researchers speaking recently at the Black Hat Briefings in Las Vegas showed that the Javascript used by most advertising networks could be compromised by a malicious third party. The malicious code could then run in any web browser configured to allow advertising.

Hold on. Wouldn’t the people responsible for the advertising networks and the associated Javascript notice the problem and fix it? Possibly. But not always. If you’re like me, you’ve seen more than a few messed up web ads. A seriously broken web ad can prevent a web page from displaying properly or cause it to load very slowly. It’s one of the many reasons why people use script blocking technology like NoScript.

It’s difficult to predict whether malware purveyors will start using the ad networks like this. But if they do, you can bet we’ll see a surge in script and ad-blocking software installations. Since advertising is the primary source of revenue on the web, this will get the attention of the advertisers, who would hopefully then institute better quality control.