Google has removed paid links that advertised seemingly legitimate Web sites but actually tried to install nefarious programs on PCs.

The links were displayed as “sponsored links” after visitors entered specific queries into Google’s search service. Clicking the links would ultimately go to a legitimate site, but by way of another site that attempted a “drive-by installation” of password-stealing software. Miscreants placed the links using Google’s AdWords service for advertisers.

“Google identified and canceled AdWords accounts displaying ads that re-directed users to malicious sites,” a company representative wrote on a corporate blog on Thursday.

The malicious links appeared after people searched for terms related to the Better Business Bureau and cars, according to Exploit Prevention Labs, a security company. All the paid-for links masqueraded as legitimate sites and redirected Google users to the actual sites after sending them to smarttrack.org, which served up the malicious code, Exploit Prevention Labs said.