[manigandham]

The entire internet is an attack vector. Malware has existed for a long time in numerous forms, ad networks are just another possibility but so are websites themselves, downloadable software, mobile apps, etc.

As mentioned in another comment - We also have cars and cellphones that can be used by criminals. That doesn't mean modern transportation and communication has a problem, it means that criminals will be criminals and we need better ways of dealing with them. As far as I can see, that's an implementation problem.

Here's the truth: I've been in the ad industry for a long time and there is literally 0 enforcement of anything. Lots of fraud and shady practices but no regulation and nobody to answer to. If you do get caught, change the name of the company and try again. I can guarantee that if we actually send people to jail for not vetting malware or running illegal or shady ads, this problem will pretty much go away immediately.