DoubleVerify warns advertisers from fraudsters exploiting ads.txt

Media effectiveness platform DoubleVerify (DV) is warning advertisers of the increasing exploitation of ads.txt – an industry standard designed to help publishers declare authorised digital inventory sellers. 

Issued in DoubleVerify’s Transparency Centre, the alert warns advertisers from fraudsters manipulating the ads.txt standard, allowing them to appear legitimate and divert adspend away from trusted publishers.

The DV Fraud Lab has identified over 100 cases of ads.txt deception since May 2017, with a significant increase in recent years. It has uncovered a network called Synthetic Echo, comprising over 200 AI-generated, ad-supported websites.

These sites use near-identical, cloned ads.txt files to mislead programmatic platforms and sometimes copy ads.txt entries directly from reputable publishers. They’re monetised through multiple SSPs and ad exchanges.

Gilit Saporta, Head of the DV Fraud Lab, said: “Bad actors are exploiting ads.txt and advertisers often have no idea it’s happening. It’s a growing risk that demands more scrutiny from buyers, sellers and vendors.” 

DV has shared best practices for publishers, which include only listing trusted direct sellers and vetted resellers; auditing ads.txt files regularly and removing outdated entries; keeping files concise; using sellers.json (which enables buyers to identify all entities) for added transparency; and monitoring domains or scripts and blocking unauthorised actors. 

For programmatic platforms – including SSPs, DSPs, and exchanges – best practices include validating ads.txt files for anomalies and duplicates before use; detecting copied or manipulated ads.txt files across domains; prioritising direct seller relationships and minimising indirect traffic; and using sellers.json and OpenRTB Supply Chain Object to confirm inventory legitimacy. 

DV also urges advertisers to maintain real-time fraud detection and share threat intelligence as well as continuously audit inventory sources and educate ecosystem participants.