Israeli digital advertising agency Discover-Tech spied on internet users through a sprawling network of online ads that it used to ​track targets and help hack their devices, two research groups said on Thursday.

Its services gave Israel's Candiru — a spyware company blacklisted by the US government — as well as ‌other Israeli surveillance firms access to advertising platforms run by Google, Comcast, Russia's Yandex and others, according to separate reports from Canadian cyber watchdog group Citizen Lab and New York advertising security firm Confiant.