New free service reveals exactly who is tracking you across websites and apps
Figuring out who is responsible for the ads shown on the websites we visit, or which companies harvest data from the mobile apps we use daily, has traditionally been a daunting task. The information is technically public, but it is scattered across multiple sources and largely locked away inside large advertising platforms. A new free service called DecryptAds aims to change that by scraping and cross-referencing adtech data, making it easy to quickly learn a great deal about the entities tracking you.
The freshly launched decryptads.com says it continuously scans the files that websites and apps make publicly available to disclose which companies are permitted to run ads or collect user data. These include ads.txt, which lists all adtech companies and data brokers that may serve ads or harvest data from a site; app-ads.txt, covering entities that can display ads or collect data from mobile and smart TV apps; and buyers.json and sellers.json, which reveal the entities buying, selling, or reselling ad inventory for a given site or app.
Zach Edwards, chief research officer at DecryptAds and a threat researcher at the security firm Infoblox, said he and two other founders decided the service was necessary because the adtech data in these files is only genuinely useful when it can be cross-referenced to build a more complete picture of the advertising ecosystem for each website or app.
"It's an adtech tool but we're trying to approach adtech from a security perspective," Edwards said. "It's really built for a lot of privacy and security use cases that have been dramatically underserved."
The service is aimed at ordinary users who want to understand who is tracking their online activity, as well as researchers and security professionals looking for a clearer view of the advertising landscape. By pulling together multiple disclosure files, DecryptAds turns scattered, hard-to-parse data into a searchable resource that answers a simple question: which companies are watching you, and where.
