Cyber crooks are using one of Google's own tools to poison search results with links that spread fake security software, a researcher said Thursday.
"Malware distributors have abused Google Trends before," said Craig Schmugar, a senior threat researcher with McAfee. "But I've never seen them use it as aggressively as they are now."
Google Trends, a tool the search giant rolled out last June, highlights the most popular searches of the past hour. At mid-day Thursday, for instance, the No. 1 search phrase, according to Trends, was "Obama budget."
Scammers and malware makers are closely monitoring Google Trends to guide them in selecting search phrases and legitimate news content, which they then integrate into their own fly-by-night sites, said Schmugar. The idea is to "game" Google into ranking their malware-hosting sites near the top on scores of high-profile, current events-related search results.
"I'm not talking about just a few sites," Schmugar said. "I've collected a lot of them, with poisoned links [in Google search results] that are pretty high up, almost always in the top 10."
News accounts recently abused by hackers have ranged from this weekend's stories about a worm spreading on Facebook to the attack last week by a chimpanzee that left a Connecticut woman in critical condition, said Schmugar. "They're grabbing content from pages that are already popular," he said. "They grab content from those pages and put it on their own site."
More recently, Schmugar has monitored poisoned links ranked high on searches for "Gmail down," a reference to the two-and-a-half hour outage at Google's Web-based e-mail service on Tuesday.
Because the malicious sites share the same content as legitimate pages which are currently of great interest -- and because the scammers also name those pages with the popular search phrases it pulls from Trends -- Google's ranking algorithms push those sites toward the top when people search for that news or use those search strings.
"It looks like they're following Trends, which refreshes every hour, and then reacting very quickly to produce their own sites," said Schmugar. The only common element he's found so far among those sites is that they are all hosted on free site hosting services. "Some portion of this must be automated," he added, to account for the quick reaction time to the hot searches and content touted by Trends.
All the poisoned links lead to sites that hit users with phony security warnings; those alerts then try to trick users into downloading a free anti-virus program. The download, however, is actually a Trojan horse that continues to duns the user with fake warnings. The only way that users can stop the messages, and to supposedly clean their PCs of infection, is to pay for the worthless software.
Distributing "scareware," as the category is sometimes called, can be very lucrative. Last year, Joe Stewart, the director of malware research at SecureWorks Inc., said he had found evidence that some hackers were making as much as US$5 million a year from the practice.
Schmugar's advice? "Look carefully before you click," he said.