You've been told repeatedly not to click on suspicious links, to prevent your computer from being infected with malware and viruses. But there's a threat you've probably never heard of that can infect your computer—even without a single click. And lawmakers are taking notice.
Experts told CNBC that advertisements on sites can be used by cybercriminals to take over your computer, steal your identity or access your online bank account. Websites are working to stop the problem, but these aggressive ads still slip by with damaging code. This kind of malicious ad—known as malvertisements—contain malware or embedded viruses, which can infect computers without a single click.
"We estimate that last year over 12.4 billion malicious ad impressions were served," said Craig Spiezle, executive director and president of Online Trust Alliance, a nonprofit that educates businesses and consumers on security and privacy issues.
Such ad impressions can compromise your computer if your browser has insecure privacy settings, said Curt Wilson, a senior research analyst at cybersecurity company Arbor Networks.
Spiezle testified at a May 15 Senate hearing on malvertising. He told the Senate subcommittee on investigations that malicious ads increased 225 percent between 2012 and 2013, though some tech companies disputed the increase.