Citizen Lab says governments are abusing online ads to hack people with ‘zero-click’ spyware

Security researchers at digital rights unit Citizen Lab say government spyware makers are abusing global advertising networks to target and hack devices by serving malicious online adverts.

A new report published Thursday by the University of Toronto lab, which investigates surveillance and digital rights abuses, said an Israeli company called Discover-Tech allows spyware makers to use its advertising platform to target specific people or devices almost anywhere in the world with spyware capable of invisibly stealing their data.

The researchers say Discover-Tech presents itself as a legitimate advertising firm, but instead serves as a “bridge between ad vendors and the mercenary spyware ecosystem.”

Citizen Lab said at least two makers of zero-click spyware, Candiru and Bindecy, used Discover-Tech’s platform to target people. Both of these spyware makers provide surveillance products that can infect devices without the victim having to open a message or click on a link.

The researchers found that one attack affected at least 45 Windows computers at media organization Al Jazeera. The devices were apparently hacked in 2024 and 2025 via Candiru’s spyware after being exposed to online ads packed with malicious code.

Citizen Lab said it wasn’t clear which governments were behind the attacks, but said this is the first confirmation of zero-click government-backed spyware attacks being delivered through online ads, potentially putting a vast number of devices around the world at risk of being targeted and hacked.

“There has been a lot of buzz that online ads can be used to identify and automatically hack targets with pinpoint precision, but now for the first time, we have concrete technical evidence showing this process in action,” said Bill Marczak, a Citizen Lab senior researcher, ahead of the report’s release.

Hackers have long sought ways to abuse access to advertising networks, in part because of their ability to reach almost any internet-connected device in the world. Ad networks are designed to help advertisers target certain kinds of people, devices, and organizations with specific ads, but they can also be abused to target specific individuals or devices with malicious code.

While such so-called “malvertising” attacks are not new, using online ads to allow powerful government spyware to silently hack into devices is a notable escalation.

Security and privacy experts have for years encouraged people to install ad-blockers to prevent ads from being displayed on desktop and mobile screens, including within apps. But the ubiquity of online advertising makes it difficult to escape the industry’s clutches entirely.

The researchers said Discover-Tech’s platform, which the company calls Controlium, left some of its source code exposed on its login pages, allowing the researchers to recreate its web-based control panel dashboard without needing to log in. The researchers say the web dashboard “appears to be specifically designed to allow them to push malicious content to individual targeted users alongside advertisements.”

Citizen Lab also found that Discover-Tech’s site had a publicly accessible portion that allowed the researchers to download reams of user login records for the Controlium dashboard without needing a password. Some login details belonged to at least two employees of spyware maker Candiru, as well as some from Bindecy.

The researchers also found billions of ad bidding records left exposed on Discover-Tech’s website, which showed that its ads had ultimately been displayed across tens of thousands of mobile apps and websites between March and June 2026.

The bidding records show that the ads were shown on devices used by militaries, governments, critical infrastructure, and national cyber agencies. However, it’s unclear if the displayed ads resulted in a compromise or infection.

Security researchers with ad quality platform Confiant, which worked with Citizen Lab to investigate, said they found evidence that potentially malicious ads were similarly shown on devices on the networks of the International Atomic Energy Agency, and the International Criminal Court.

Citizen Lab’s Marczak said Discover-Tech is “surely just the tip of the iceberg,” and urged people to take defensive action. 

“If you might be targeted based on who you are or what you do, it’s time to disable ad tracking on your devices or even block ads altogether,” said Marczak.

Al Jazeera did not respond to a request for comment about the hacks. Neither did Discover-Tech, and Candiru maker Integrity Labs could not be reached for comment.