Malvertising, or malicious advertising, is the use of online advertising to distribute malware with little to no user interaction required. In just the first half of 2015, malvertising increased 260% compared against all of 2014. In 2015, Google disabled more than 780 million bad ads, a nearly 50% increase over 2014. The FBI, Department of Justice, and Homeland Security have pledged to get involved. Practice safe Internetting, and you could still be vulnerable, but you can’t avoid malvertising.”]
Source: https://blog.malwarebytes.com/101/2016/06/truth-in-malvertising-how-to-beat-bad-ads/