It was a case of spies watching spies watching spies: Israeli intelligence officers looked on in real time as Russian government hackers searched computers around the world for the code names of American intelligence programs.
What gave the Russian hacking, detected more than two years ago, such global reach was its improvised search tool — antivirus software made by a Russian company, Kaspersky Lab, that is used by 400 million people worldwide, including by officials at some two dozen American government agencies.
The Israeli officials who had hacked into Kaspersky’s own network alerted the United States to the broad Russian intrusion, which has not been previously reported, leading to a decision just last month to order Kaspersky software removed from government computers.
“Antivirus is the ultimate back door,” Blake Darché, a former N.S.A. operator and co-founder of Area 1 Security. “It provides consistent, reliable and remote access that can be used for any purpose, from launching a destructive attack to conducting espionage on thousands or even millions of users.”
On Sept. 13, the Department of Homeland Security ordered all federal executive branch agencies to stop using Kaspersky products, giving agencies 90 days to remove the software. Acting Department of Homeland Security Secretary Elaine C. Duke cited the “information security risks” presented by Kaspersky and said the company’s antivirus and other software “provide broad access to files” and “can be exploited by malicious cyber actors to compromise” federal computer systems.
That directive, which some officials thought was long overdue, was based, in large part, on intelligence gleaned from Israel’s 2014 intrusion into Kaspersky’s corporate systems.
Kaspersky Lab did not discover the Israeli intrusion into its systems until mid-2015, when a Kaspersky engineer testing a new detection tool noticed unusual activity in the company’s network.
The report did not name Israel as the intruder but noted that the breach bore striking similarities to a previous attack, known as “Duqu,” which researchers had attributed to the same nation states responsible for the infamous Stuxnet cyberweapon.
Stuxnet was a joint American-Israeli operation that successfully infiltrated Iran’s Natanz nuclear facility, and used malicious code to destroy a fifth of Iran’s uranium centrifuges in 2010.
Kaspersky reported that its attackers had used the same algorithm and some of the same code as Duqu, but noted that in many ways it was even more sophisticated. So the company researchers named the new attack Duqu 2.0, noting that other victims of the attack were prime Israeli targets.
Among the targets Kaspersky uncovered were hotels and conference venues used for closed-door meetings by members of the United Nations Security Council to negotiate the terms of the Iran nuclear deal.
Kaspersky’s researchers noted that attackers had managed to burrow deep into the company’s computers and evade detection for months. Investigators later discovered that the Israeli hackers had implanted multiple back doors into Kaspersky’s systems, employing sophisticated tools to steal passwords, take screenshots, and vacuum up emails and documents.
In its June 2015 report, Kaspersky noted that its attackers seemed primarily interested in the company’s work on nation-state attacks, particularly Kaspersky’s work on the “Equation Group” — its private industry term for the N.S.A. — and the “Regin” campaign, another industry term for a hacking unit inside the United Kingdom’s intelligence agency, the Government Communications Headquarters, or GCHQ.
Israeli intelligence officers informed the N.S.A. that in the course of their Kaspersky hack, they uncovered evidence that Russian government hackers were using Kaspersky’s access to aggressively scan for American government classified programs, and pulling any findings back to Russian intelligence systems. They provided their N.S.A. counterparts with solid evidence of the Kremlin campaign in the form of screenshots and other documentation, according to the people briefed on the events.