Ciaran Martin, chief executive of Britain’s National Cyber Security Center, said Russia had targeted “millions” of devices in both countries, often seeking to hack into individual homes or small businesses or to control their routers.
“Once you own the router, you own all the traffic, to include the chance to harvest credentials and passwords,” said Howard Marshall, deputy assistant director of the cyber division at the Federal Bureau of Investigation. “It is a tremendous weapon in the hands of an adversary.”
In particular, both governments said, the Russians were seeking to exploit the increasing popularity of internet-connected devices around homes and businesses — the so-called internet of things — “the kind of thing you and I have in our homes,” Mr. Joyce said.
The officials said the Kremlin was often utilizing what were known as man-in-the-middle attacks, in which hackers secretly inserted themselves into