Chinese hackers tried to break into phones linked to Donald Trump's election campaign.
Officials said the attacks hit staffers, including vice presidential candidate Vance.
It is not known whether the hackers managed to gain access to the phones,The Washington Post writes.

However, there is information that they attacked the devices of some team members.
People associated with the campaigns of Kamala Harris and Minnesota Gov. Tim Walz have also been targeted.
The Federal Bureau of Investigation notified the Trump and Vance campaigns of the incidents.
It is not yet clear whether these attacks directly affected Harris or Waltz.
The FBI said hackers targeted some media representatives and prominent Americans.
The United States believes that targeting candidates for espionage purposes is standard practice among world powers.
US officials said they did not consider the latest efforts to be election interference.