Google is going after malware-spreading advertisers more aggressively with the quiet launch of a free service that lets Website owners run background checks on potential online advertisers.

Anti-Malvertising, which yesterday received a face-lift with additional resources and a higher profile, is a custom search engine that lets you check if an online advertiser is known to have spread malware-laden advertisements.

Attackers are increasingly using legitimate Websites to spread their malware, either hiding it within an ad itself, embedding it on the page, or using a download link to infect victims.

Eric Davis, a member of Google's Anti-Malvertising Team, says the custom search engine originally went live in February, but Google yesterday relaunched the site with more information and content. "We created Anti-Malvertising.com to help ad publishers and Internet users learn more about malvertising threats," Davis says.

The search engine checks third-party sites that track ad malware. "What's new as of yesterday is that we redesigned the site and added new, expanded educational content to supplement the custom search engine" so ad publishers and Internet users can better protect themselves, Davis says.

Bottom line: Google wants to keep the online advertising "ecosystem" clean.

"The overall site fits into our broader goal to help and encourage all members of the online advertising ecosystem to take an active role in malvertising prevention," Davis says.

Still, Google warns that the custom search engine is just one source of badware information. "Its search results should not be considered the last word on a prospective customer, but one potential source of helpful information. If a party you're researching comes up in a search result here, we recommend you take a closer look at the party in question before rendering judgment," Google's site says.

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