AdWords is the contextual advertising division of Google that allows an advertiser to create ads, choose keywords and pay only when someone clicks on them. The program was developed in 2000 with the official launch of AdWords Select™ taking place in January 2002. The advertising system is widely thought to be the cornerstone of Google’s revenue.

Beginning Thursday, February 3, 2005, apparently several keywords across multiple search topics have been attacked. Such search terms as “web hosting,� “irs,� “mortgage� and even “ebay� have resulted in significantly fewer AdWords contextual placements appearing in search results.

ClickRisk, a click fraud consulting service, issued a Google AdWords advisory on February 2nd that botnets are able to “shut down or seriously impair a Google Adwords advertising campaign by artificially inflating the number of times an ad is displayed.� This in turn would cause AdWords to automatically disable the targeted keywords essentially shutting down the campaign for those words.

Adam Sculthorpe, security specialist and CEO of Clickrisk.com, and his team of 19 researchers have discovered through extensive forensic testing and analysis of Google Adwords, a new type of click fraud—Keyword Hijacking. Keyword Hijacking is where an attacker disables campaign keywords to secure a higher ad position. Sculthorpe explains, “this is achieved by disabling targeted keywords across many advertisers’ campaigns simultaneously by artificially inflating the number of times an ad is displayed.�

Speculation as to the cause throughout many blogs and forums has been wide and far. One such example has regarded botnets using Google’s AdWords API beta (a service that lets applications created by developers, advertisers and third parties to more efficiently - and creatively - manage their large AdWords accounts and campaigns directly with the AdWords server) to disrupt the system. Another speculation has connected Google's recent ICANN accreditation to the AdWords attack.

The AdWords attack has potential far reaching affects. From Google investors losing ad revenue across multiple industries to the industries themselves, the dollar figure could be astronomical. Trey Gardner, Online Marketing Manager at Globat.com said “Overall hundreds of hosting providers and web hosting directories spend tens of thousands of dollars every day to attract the thousands of potential customers searching the “web hosting� key term in Google…the percentage loss of new customers today may have been greater than 15%.�