Webcake adware inserts an AT&T ad into the YouTube site without permission from Google.
Ad injectors insert ads into others’ sites, without permission from those sites and without payment to those sites. In this article, we review the basic operation of ad injectors, then examine the ad networks, exchanges, and other intermediaries that broker the placement of advertising through injectors.
We also report which advertisers most often advertise through injectors. Whether through complexity, inattention, or indifference, these advertisers’ expenditures are ultimately the sole revenue source for injectors.