Even hackers find AdWords effective
There is a popular hacking tool called “MPack” that apparently uses Javascript to stuff non-displayed keywords into web pages. And its being sold to the public.
Read more about hackers using adwords
Along with the invisible <IFRAME> element, they inject non-displayed words into the HTML code of sites’ front pages - perhaps words that may not have anything to do with the sites’ native contexts. Then they use a portion of their income from sales to purchase sponsored links from Google AdWords, matching those words with users’ searches to direct them to those sites. (Hypothetical example: “More about Paris Hilton in jail at UsedFerraris.it”)
The AdWords system itself is does not appear to be exploited but instead is used to lure unsuspecting users to the sites containing malware. If I am Google, I am giving serious thought to a monitoring process for this type of activity.


