Earlier quoted context omitted.
Just because code/webpages are delivered to you over the web doesn't mean you can take them and republish them somewhere else.
Is illegal code (i.e. malware) protected by the copyright to begin with? If it is, then all antiviruses blatantly violate copyright. But something tells me they don't need to ask any permission from malware authors.
But that begs the question, as ad injectors are probably not illegal.
[1] http://www.cardozo.yu.edu/sites/default/files/Eldar%20Haber,...