Fraud taxonomy
General and Sophisticated Invalid Traffic
Known data-centre traffic
Bots and spiders or other crawlers
Activity-based filtration
Non-browser user-agent headers or other forms of unknown browsers
Pre-fetch or browser pre-rendered traffic
Bots and spiders or other crawlers masquerading as legitimate users
Hijacked devices, user sessions, ad tags and ad creatives
Hidden/stacked/covered or otherwise intentionally obfuscated ad serving
Invalid proxy traffic
Adware + Malware
Incentivised manipulations of measurements
Falsified viewable impression decisions
Falsely represented sites
Cookie stuffing, recycling or harvesting
Manipulation or falsification of location data
Invalid Impressions