NSO Group’s motto is “Make the World a Safer Place.” But its spyware is increasingly turning up on the phones of journalists, dissidents and human rights activists.

NSO spyware was discovered on the phone of a human-rights activist in the United Arab Emirates and a prominent Mexican journalist in August. Researchers at the Citizen Lab at the University of Toronto’s Munk School of Global Affairs discovered NSO had exploited flaws in Apple software — since patched — to infiltrate the phones of the Emirati activist and the Mexican journalist, Rafael Cabrera.

In 2015, Mr. Cabrera reported that a luxury home that had been custom-built for President Enrique Peña Nieto of Mexico and his wife was owned by the subsidiary of a Chinese company that had been awarded hundreds of millions of dollars in government contracts. Mr. Cabrera’s report forced the presidential couple to forgo its stake in the home and the government to rescind contracts.

The discovery of spyware on Mr. Cabrera’s phone prompted digital rights activists to warn more journalists and activists in Mexico to look out for similarly suspicious text messages. In the process, they uncovered a new class of targets: nutrition policy makers and activists, some of whom were government employees.

Each had been targeted by NSO’s main product, a tracking system called Pegasus, that could extract their text messages, contact lists, calendar records, emails, instant messages and location. It turned their phones into recording devices and secretly captured live footage off their cameras. Its full range of capabilities was detailed in an NSO Group marketing proposal leaked to The Times last year.

In interviews and statements, NSO Group — whose headquarters are in Herzliya, Israel, but which sold a controlling stake in 2014 to Francisco Partners, a San Francisco-based private equity firm — claims to sell its spyware only to law enforcement agencies to track terrorists, criminals and drug lords. NSO executives point to technical safeguards that prevent clients from sharing its spy tools.