A report said that Boris Johnson's office was the target of multiple suspected cyberattacks.
According to a report published Monday by the University of Toronto's Citizen Lab, Number 10 was believed to have been targeted with a hacking software that can turn a phone into a remote listening device.
There were also suspected attacks on the Foreign, Commonwealth and Development Office, as well as India, Cyprus and Jordan, over the same period.
The Israeli firm NSO Group developed, marketed, and licensed to governments around the world a hacking software called Pegasus. It has the ability to cause harm to phones running either operating systems.
According to a report by The New Yorker, a device connected to the Downing Street network was compromised in 2020.
John Scott-Railton, a senior researcher at the Citizen Lab, told the magazine that when they found the Number 10 case, his jaw dropped.
In a statement published on its website, Citizen Lab director Ron Deibert said that the team had taken the unusual step of notifying officials because they believed that their actions could reduce harm.
The group was not able to identify the individuals who are suspected of having been hacked.
The FCDO attack could be similar to the hacking of foreign phone numbers used by US State Department employees in Uganda. The attack was carried out by an unknown person using a piece of software developed by NSO Group.
The NSO Group was blacklisted by the Biden administration in November of 2021, after it was determined that the Israeli company had acted contrary to the foreign policy and national security interests of the US.
The UK government took appropriate action to mitigate the threat after a lawyer in the UK was hacked by NSO Group.
Concerns about telecommunications security have been raised before.
The phone number of the prime minister was freely available online for a decade.
Insider reported in March that Johnson was receiving digested versions of his red box on a daily basis, prompting further security concerns.