Types of Ad Fraud

05/11 By IAS Insider
Introduction to Ad Fraud

Digital ad fraud prevents the proper delivery of ads to the intended audience, in the intended place. It can lead to wasted advertiser spend and damaged reputations for publishers.

But what are the types of fraud out there? Look no further, as we explain the main types of ad fraud you are likely to come across in digital advertising.

And – just before we get stuck in, make sure to check out the IAS Ad Fraud Guide, where we explain these types in full and of course, for top tips on how to combat those pesky fraudsters.


Short for robots, hackers create bots to surf the web, click on ads and play videos, which drives up traffic, resulting in more money paid out to the fraudsters. These bots are viruses that can be installed unknowingly on a computer. However, most people with infected computers are completely unaware.

 Domain spoofing

Domain spoofing is a form of fraud where a fraudster impersonates a company’s domain in order to pass off low quality inventory as high quality. Fraudsters fool buyers into thinking their ad is going to a premium site, when in reality it’s going to a low-quality website. Domain spoofing is also commonly used to mask unsafe sites.

Pixel Stuffing

Serving one or more ads, or an entire ad-supported site, in a single 1×1 pixel frame so ads are invisible to the naked eye.

Ad Stacking

Placing multiple ads on top of each other in a single placement, with only the top ad being viewable. The advertiser is paying for impressions even if the user is not seeing the ads.

Location Fraud

Advertisers pay a premium for their ad to be served in a particular region, but fraudsters will send false location information so the ad actually serves elsewhere.

Cookie Stuffing

Cookies are a method of tracking user behaviour, to help determine what advertising effort led to a conversion (click, purchase, etc.) or what a user’s interests are.

User-Agent Spoofing

The web page “header”, that provides a description of the browser, is modified to obfuscate information about the browser being used, which can interfere with user targeting. It’s most often used by bots trying to hide their tracks.

Key Takeaways to combat Ad Fraud

    • The most prevalent forms of ad fraud are illegal bots and domain spoofing.
    • Bots are viruses that can be installed unknowingly on a computer and that use computer resources in an unnoticeable way
    • Domain spoofing is when fraudsters fool buyers into thinking their ad is going to a premium site, when instead it’s going to a low-quality website.
    • Different methods of ad fraud can be combined for maximum effect and maximum profit gain.

Learn how to combat Ad Fraud with IAS here.