Another way compromised smartphones can be exploited is by turning cameras and microphones of a hacked phone into a secret spycam in which an adversary surreptitiously and remotely watches or eavesdrops on the targeted device's owner.
Director of National Intelligence James Clapper last week called out Russian intelligence services as a "leading" cyber threat to U.S. interests in his statement to a Senate hearing on the major security challenges facing the nation.
"Sophisticated foreign intelligence entities will continue to employ human and cyber means to collect national security information," Clapper said.
But while personal information is also at risk, Shawn Henry, a CrowdStrike senior executive, said it probably won't be high on the Russian' domestic intelligence services' list of priorities because they'll be busy trying to prevent Chechen Islamist militants from attacking the Olympic venue in Sochi or other targets over the next few weeks.
"People should be aware that their data is accessible because it's traveling on infrastructure controlled by the [Russian] government," said Henry, a former FBI executive assistant director at the head of computer crime and cybersecurity. "But they have limited resources and a much bigger threat there."
ABC News' Kirit Radia contributed reporting from Moscow.