Citizen Lab investigation says dozens of Al Jazeera devices were infected by malware planted through advertisements.

Israeli advertising technology company Discover-Tech helped place spyware on dozens of devices used by Al Jazeera and other companies, a Citizen Lab investigation prompted by Al Jazeera’s initial internal probe has confirmed.

Al Jazeera Media Network on Thursday said it “condemns the targeting of devices belonging to several of its employees with spyware” and pledged to continue to “protect its employees and systems”.

The network said targeting journalists is an “assault on press freedom and the public’s right to knowledge” and called for those responsible to be held accountable.

Spyware from Candiru, a firm blacklisted by the United States government in 2021 for its malicious cyber activities, was planted on these devices, using what Citizen Lab described as the first-known instance of “zero-click” targeted advertising.

The Citizen Lab, an interdisciplinary research unit at the University of Toronto, concluded in its report that Discover-Tech purchased the advertisements with built-in spyware. It then directed devices to Candiru’s malware through these advertisements.

The millions of directed devices include those belonging to Al Jazeera’s journalists – including several who reported on sensitive subjects.

Al Jazeera’s internal technology team first discovered unusual patterns on devices used by some journalists in 2024. The pattern continued into 2025. Al Jazeera reached out to Citizen Lab for a more detailed investigation into its suspicions that spyware was responsible for the activity.

“Analysis of network logs provided to the Citizen Lab by Al Jazeera collected during the attack period provides a clear temporal signature of how the attack was executed,” the University of Toronto-based team said its report published Thursday.

Al Jazeera said that the cooperation “contributed to verifying these attacks and publicly documenting them”.

The “zero-clock” nature of installing this spyware means that once an infected advertisement appears on a device, that device, too, is infected — spying on, and feeding, all the data and information available on that platform to those stealing it.

Meanwhile, New York-based security firm Confiant said in a separate report that some of Discover-Tech’s advertisements also appeared in critical networks used by the Pentagon, the International Atomic Energy Agency and the International Criminal Court.

Candiru’s spyware has previously been used to carry out surveillance on at least 100 journalists, dissidents and others in several countries.