Is the placement serving AdSense only or has it passed the quality assurance of other networks? Less quality checks mean more room for fraud. Is the PublisherId part of a network where fraud was detected in the past? This is data you can extract from the ads.txt file.
IP Lookup and Enrichment
In which country is the placement hosted? Which hosting provider is used? What is the connection speed? Are there multiple placements running on the same IP Address? Fraud placements love cheap hosting and share there IP Address with other placements.
Publisher ID Analysis
If you make money with “fraudy” placements you will probably have more than one website. By checking our Publisher ID Database we are able to draw connections between different placements. Even when they are hosted in completely different environments.
The Placement looks like a website build 20 years ago? The content is very thin and stuffed with keywords and Ad Slots all over the place? If there is no chance to rank in any organic search engine the probability of getting low quality traffic form those placements is very high!