China may have hacked data from every single American in one of the largest-ever cyberattacks, experts fear.

Hackers backed by Beijing targeted more than 80 countries, stealing information on telecoms, transport and military infrastructure in a year-long campaign, investigators concluded in a report released last week.

Since 2021, the group, known as Salt Typhoon, has accessed data that could enable the Chinese intelligence services to monitor global communication networks and track targets including politicians, spies and activists.

Even the telephone conversations of Donald Trump and JD Vance were compromised, according to the FBI.

Hackers sponsored by the Chinese government “are targeting networks globally, including, but not limited to, telecommunications, government, transportation, lodging, and military infrastructure networks”, the joint statement, from agencies including the National Security Agency, Cybersecurity and Infrastructure Security Agency (CISA) and FBI, said.

The attack was “unrestrained” and “indiscriminate”, according to British and American officials.

“I can’t imagine any American was spared given the breadth of the campaign,” Cynthia Kaiser, a former top cyber official in the FBI, who oversaw investigations into the hacking, told The New York Times.

The breach was first uncovered last summer by Microsoft cybersecurity employees and has been linked to at least three China-based security companies operating since 2019.

According to the statement, these companies work for China’s military and civilian intelligence services, giving Beijing the capability to identify and track their targets’ communications and movements around the world.

The full extent of the attack was not immediately understood, but investigators soon realised it stretched to the highest levels of politics and national security.

Mr Trump and Mr Vance’s phones were targeted during last year’s presidential campaign, potentially giving Beijing access to their call and text records.