The chairman of the Senate Intelligence Committee said hackers listened to phone calls and read texts by exploiting aging equipment and seams in the networks that connect systems.

Phones used by Jared Kushner and Eric Trump were among those that hackers sought access to as part of a counterintelligence effort carried out by a hacking group associated with China.

A group that experts call Salt Typhoon is believed to be behind a sophisticated breach of major telecommunication companies that has taken aim at American leaders.

The targeting of the Republican presidential ticket’s phones is part of what appears to be a wide-ranging effort to gather information about American leaders.