Chinese-linked hackers accessed surveillance data meant for U.S. law enforcement after infiltrating the networks of several telecom companies, according to a statement from U.S. authorities on Wednesday.

US officials believe Chinese hackers breached at least eight US telecommunications providers in their quest to spy on top US political figures as part of a hacking campaign that has affected dozens of countries worldwide,

At least eight U.S. telecommunications firms were compromised in the attack, a senior White House official said.

At least eight U.S. telecom firms have been compromised by a Chinese hacking campaign, a White House official said on Wednesday. The hack, which also affected dozens of other countries, is part of the ongoing and sprawling “Salt Typhoon” campaign – a cyber campaign that the U.

This is the first time the U.S. has confirmed the number of carriers reeling from the Salt Typhoon campaign — more than three months after news reports started uncovering details about the operation.