Israeli digital advertising agency Discover-Tech used a sprawling network of online ads to identify and track internet users and help hack their devices, Canadian cyber watchdog Citizen Lab and New York advertising security firm Confiant said on Thursday. Its services gave Israeli spyware firm Candiru and other surveillance companies access to ad platforms run by Google, Comcast, Yandex and others.The reports said the online advertising industry, already under scrutiny over privacy, could serve as a channel for extensive espionage. Discover-Tech’s ads, often promoting ordinary products such as phones or earpods, reached more than 120,000 websites and 75,000 apps through its partnerships, Citizen Lab said.Users visiting sites or using apps carrying the malicious ads could be identified and tracked by Discover-Tech, which sometimes tried to extract phone numbers from smartphone users, researchers said. The ads only had to load for the surveillance to occur. Some also helped install Candiru spyware on devices, although Confiant said these made up a tiny fraction of Discover-Tech’s volume.Confiant co-founder Jerome Dangu said Discover-Tech distributed at least 10 million ads daily worldwide and used data-sharing arrangements known as cookie matching to track people beyond their reach. “Very likely hundreds of millions of people would have been touched by Discover-Tech,” Dangu said.Discover-Tech, founded in 2020, did not respond to messages, while attempts to reach chief executive Dekel Boni and Candiru’s owners were unsuccessful. US commerce department blacklisted Candiru in 2021, alleging it supplied spyware used to maliciously target govt officials, journalists, activists and academics.Citizen Lab said Candiru spyware delivered through Discover-Tech ads compromised 45 Windows devices at Qatari broadcaster Al Jazeera between 2024 and 2025. It said it confirmed the attacks using network logs shared by the broadcaster. Al Jazeera did not respond.Dangu said malicious ads appeared on hundreds of networks in sensitive categories, including Pentagon, International Atomic Energy Agency and International Criminal Court. He said Palestinian territories were particularly saturated, adding: “You go to almost any site in Palestine – any site – you find a Discover-Tech ad. It gives them a very complete visibility on the digital activities of an entire country,” he said.Citizen Lab said it had similar evidence that the ads were shown to people in UN, Nato, European Commission and more than a dozen national govts. They also appeared on networks of chip companies including Nvidia, Sandisk, Broadcom and Micron, and unidentified media organisations in Mexico, Israel and Europe.Google said it had worked with both investigators and removed Discover-Tech from its ad platforms “for systematically violating our policies.” IAB Europe suspended it from its approved-vendor list after an audit, while Comcast subsidiary Beeswax removed it from its platform. Yandex did not respond.