Scammers tricked the New York Times' Digital Advertising department into placing a malicious ad for fake antivirus software on the NYTimes.com Web site over the weekend, the company confirmed Monday.
The newspaper had warned of the scam advertisement Sunday, after receiving about 100 e-mails from concerned readers.
According to the Times, the scammers initially claimed to be Internet phone provider Vonage, and had placed what appeared to be legitimate Vonage ads on the Web site.
However, sometime over the weekend, they switched these ads for aggressive pop-up advertisements that tried to trick victims into thinking that their computers were infected.
The point of the scam was to sell worried computer users a product called Personal Antivirus, a fake "scareware" product that bombards victims with popup ads until they either hand over their credit card information or somehow manage to remove the program.
When the complaints started pouring in, the Times first suspected that the ad had been unauthorized, and pulled third-party advertisements from the site.
But on Monday spokeswoman Diane McNulty confirmed that the ad had been submitted directly to the company's online ad department.
"The culprit masqueraded as a national advertiser and provided seemingly legitimate product advertising for a week," she said via email.
"Over the weekend, the ad being served up was switched so that an intrusive message, claiming to be a virus warning from the reader's computer, appeared."
Technology executive Troy Davis was hit with the ad after he clicked on a Times story about Dubai on Saturday night.
After his antivirus software warned him not to visit the article, he performed an analysis of the site and discovered that the Times was allowing advertisers to embed an HTML element known as an iframe into their advertisements.
This gave the criminals a way to include embedded Web pages in their copy that could be hosted on a completely different server, outside of the control of the Times.
That code redirected Davis's browser to the Web site that served a pop-up ad designed to look like a Windows system scan that had found security problems on his system.
It was, of course, all just a fake.