SAN FRANCISCO >> In the past five years, Ahmed Mansoor, a human-rights activist in the United Arab Emirates, has been jailed and fired from his job, along with having his passport confiscated, his car stolen, his email hacked, his location tracked and his bank account robbed of $140,000. He has also been beaten, twice, in the same week.

Mansoor’s experience has become a cautionary tale for dissidents, journalists and human rights activists. It used to be that only a handful of countries had access to sophisticated hacking and spying tools. But these days, nearly all kinds of countries, be they small, oil-rich nations like the Emirates, or poor but populous countries like Ethiopia, are buying commercial spyware or hiring and training programmers to develop their own hacking and surveillance tools.

The barriers to join the global surveillance apparatus have never been lower. Dozens of companies, ranging from NSO Group and Cellebrite in Israel to Finfisher in Germany and Hacking Team in Italy, sell digital spy tools to governments.

A number of companies in the United States are training foreign law enforcement and intelligence officials to code their own surveillance tools. In many cases these tools are able to circumvent security measures like encryption. Some countries are using them to watch dissidents. Others are using them to aggressively silence and punish their critics, inside and outside their borders.

“There’s no substantial regulation,” said Bill Marczak, a senior fellow at the Citizen Lab at the University of Toronto’s Munk School of Global Affairs, who has been tracking the spread of spyware around the globe. “Any government who wants spyware can buy it outright or hire someone to develop it for you. And when we see the poorest countries deploying spyware, it’s clear money is no longer a barrier.”

Marczak examined Mansoor’s emails and found that, before his arrest, he had been targeted by spyware sold by Finfisher and Hacking Team, which sell surveillance tools to governments for comparably cheap six- and seven-figure sums. Both companies sell tools that turn computers and phones into listening devices that can monitor a target’s messages, calls and whereabouts.

In 2011, in the midst of the Arab Spring, Mansoor was arrested with four others on charges of insulting Emirate rulers. He and the others had called for universal suffrage. They were quickly released and pardoned after international pressure.

But Mansoor’s real troubles began shortly after his release. He was beaten and robbed of his car, and $140,000 was stolen from his bank account. He did not learn that he was being monitored until a year later, when Marczak found the spyware on his devices.

“It was as bad as someone encroaching in your living room, a total invasion of privacy, and you begin to learn that maybe you shouldn’t trust anyone anymore,” Mansoor recalled.

Marczak was able to trace the spyware back to the Royal Group, a conglomerate run by a member of the Al Nahyan family, one of the six ruling families of the Emirates. Representatives from the Emirates Embassy in Washington said they were still investigating the matter and did not return requests for further comment.

Invoices from Hacking Team showed that through 2015, the Emirates were Hacking Team’s second-biggest customers, behind only Morocco, and they paid Hacking Team more than $634,500 to deploy spyware on 1,100 people. The invoices came to light last year after Hacking Team itself was hacked and thousands of internal emails and contracts were leaked online.

Eric Rabe, a spokesman for Hacking Team, said his company no longer had contracts with the Emirates. But that is in large part because Hacking Team’s global license was revoked this year by the Italian Ministry of Economic Development.

For now, Hacking Team can no longer sell its tools outside Europe, and its chief executive, David Vincenzetti, is under investigation for some of those deals.

New evidence suggests to Marczak that the Emirates may now be developing their own custom spyware to monitor their critics at home and abroad.

“The UAE has gotten much more sophisticated since we first caught them using Hacking Team software in 2012,” Marczak said. “They’ve clearly upped their game. They’re not on the level of the United States or the Russians, but they’re clearly moving up the chain.”

Late last year, Marczak was contacted by Rori Donaghy, a London-based journalist who writes for the Middle East Eye, an online news site, and a founder of the Emirates Center for Human Rights, an independent organization that tracks human rights abuses in the Emirates. Donaghy asked Marczak to examine suspicious emails he had received from a fictitious organization called the Right to Fight. The emails asked him to click on links about a panel on human rights.

Marczak found that the emails were laden with highly customized spyware, unlike the off-the-shelf varieties he has become accustomed to finding on the computers of journalists and dissidents. As Marczak examined the spyware further, he found that it was being deployed from 67 different servers and that the emails had baited more than 400 people into clicking its links and unknowingly loading its malware onto their machines.

He also found that 24 Emiratis were being targeted with the same spyware on Twitter. At least three of those targeted were arrested shortly after the surveillance began; another was later convicted of insulting Emirate rulers in absentia.

Marczak and the Citizen Lab plan to release details of the custom Emirates spyware online Monday. He has developed a tool he called Himaya — an Arabic word that roughly means “protection” — that will allow others to see if they are being targeted as well.

Donaghy said he was frightened by Marczak’s findings, but not surprised.

“Once you dig beneath the surface, you find an autocratic state, with power centralized among a handful of people who have increasingly used their wealth for surveillance in sophisticated ways,” Donaghy said.

© 2016 The New York Times Company