The Dark World of Adtech: New Service Sheds Light on Who’s Tracking You
A new free service called DecryptAds has launched, making it easier for anyone to uncover who’s tracking them online. By scraping and correlating publicly available data from websites and apps, DecryptAds reveals the complex web of companies involved in adtech, including those collecting sensitive personal information and geolocation data.
The service is particularly useful for individuals seeking to understand how their personal data is being used, as well as security researchers and investigators looking to track down malicious ads or identify supply-chain integrity issues. According to DecryptAds’ chief research officer Zach Edwards, the platform was created because adtech data is often only useful when cross-referenced with other sources.
DecryptAds works by analyzing files such as ads.txt, app-ads.txt, buyers.json/sellers.json, and others that websites and apps make publicly available to disclose their advertising partners. These files can be difficult to decipher, especially for those without technical expertise, but DecryptAds simplifies the process by correlating this data and making it easy to quickly learn about the entities involved.
A search on DecryptAds reveals that espn.com has 143 ad partners and 19 registered data broker domains listed within its ads.txt and app-ads.txt files. Of these data brokers, almost half are collecting geolocation data from visitors who aren’t blocking ads, while three others disclose collecting device fingerprints and sensitive personal information.
One of the most concerning aspects of DecryptAds is its ability to identify high-risk ad partners based in “geo-risk” areas such as China and Russia. A search on espn.com reveals that it works with four different advertising entities from these regions, including Between Digital, which lists a New York address but has been flagged as a Russian firm.
DecryptAds also highlights the complex supply chain involved in adtech, making it difficult to detect malicious actors or identify potential security threats. The service’s creators believe that by shedding light on this dark world of adtech, they can help individuals and organizations better understand how their data is being used and make more informed decisions about online security.
For those concerned about online tracking, DecryptAds offers a valuable resource for understanding the complex web of companies involved in adtech. As Edwards notes, “Supply-chain integrity issues rarely live in a single file; they show up as broken cross-references between multiple files.” By using DecryptAds, individuals can gain a better understanding of who’s tracking them online and take steps to protect themselves.
Ultimately, DecryptAds is a powerful tool for anyone interested in understanding the world of adtech. Whether you’re a concerned citizen or a security researcher, this new service provides valuable insights into the complex web of companies involved in online advertising. By using DecryptAds, individuals can make more informed decisions about their online activities and take steps to protect themselves from potential security threats.
Source: Krebs on Security — 2026-08-14