Military-grade spyware licensed by an Israeli firm to governments for tracking terrorists and criminals was used in attempted and successful hacks of 37 smartphones belonging to journalists, human rights activists, business executives and two women close to murdered Saudi journalist Jamal Khashoggi, according to an investigation by The Washington Post and 16 media partners.

The phones appeared on a list of more than 50000 numbers that are concentrated in countries known to engage in surveillance of their citizens and also known to have been clients of the Israeli firm, NSO Group, a worldwide leader in the growing and largely unregulated private spyware industry, the investigation found.

The list does not identify who put the numbers on it, or why, and it is unknown how many of the phones were targeted or surveilled. But forensic analysis of the 37 smartphones shows that many display a tight correlation between time stamps associated with a number on the list and the initiation of surveillance, in some cases as brief as a few seconds.