I see these every once in a while. Advertisers occasionally think it’s clever to make their ad mimic the OS interface in hopes that novice users get confused and click on it. I’m sure this is (sadly) pretty successful despite being rather deceptive. It becomes comical when these ads show up on a Mac since it looks so out of place as shown in this image.
You can’t really expect a Mac user to fall for this. It looks pretty strange. The best part is how for Operating System, it says “unknown”.
if (navigator.appVersion.indexOf("Win")!=-1){
showAd();
} else {
// Don’t even waste your time.
}