The fastest route to front-line intelligence may be in the pocket of a soldier. At least that’s according to a new report from the Wall Street Journal, which cites U.S. and European officials who say Russia has been attempting to hack the smartphones of NATO troops.

How do you hack a soldier’s smartphone? According to the report, by using “sophisticated drones equipped with surveillance electronics.” That level of technical requirement is apparently what has military officials convinced that the attacks, which have targeted soldiers on the border between Europe and Russia, are being carried out by the Russian state rather than independent hackers.

Some soldiers have apparently found their Facebook accounts on their phones hacked, while others have had the phones themselves hijacked and reported as lost. While the hacks may not directly reveal sensitive data, they could be used to ascertain location, identity, and movement of troops on the ground.

To find out more about Russia’s approaches to developing cyberweapons, read our recent feature about how the nation is reinventing old military techniques for a new century.