Suspected Russian spies are generating photographs of fake faces with computer programmes to gather information on social media, experts believe.
An AP investigation has discovered a “vast army” of phony profiles on the professional networking site LinkedIn.
Some of the profile pictures appear to show eerily realistic faces that do not belong to real humans but were rather generated by a computer.
“Katie Jones,” supposedly a 30-year-old “Russia and Eurasia fellow” at the Centre for Strategic and International Studies in Washington, virtually befriended dozens of pundits at prominent think tanks as well as a senator's aide and a deputy assistant security of state.
In fact, the centre said it knew of no such fellow, and experts who analysed the profile photograph said it was probably fake.
One of those who accepted a friend request from the account was economist Paul Winfree, a former adviser to Donald Trump who is being considered for a seat on the Federal Reserve.
While it's unclear who created the profile, some believe a foreign intelligence agency was to blame.
Alarm bells were first raised when “Katie Jones” sent a friend request to Keir Giles, a Russia specialist with London’s Chatham House think tank.
Mr Giles found the request suspicious as he had recently been targeted by an espionage operation against critics of the Russian antivirus firm Kaspersky Lab.
“It smells a lot like some sort of state-run operation,” Jonas Parello-Plesner, programme director at the Denmark-based think tank Alliance of Democracies Foundation who was also targeted by suspected foreign spies on LinkedIn, told AP.
The US National Counterintelligence and Security Centre said China in particular had been conducting “mass scale” spying on LinkedIn, with agents sending friend requests to thousands of targets.
Former CIA officer Kevin Mallory, who was sentenced to 20 years in prison in May for passing secrets to Beijing, was recruited after a Chinese agent contacted him on LinkedIn.
While the face on the Jones account looks natural, closer inspection revealed strange skin textures on the cheeks and ears and eyes that were slightly off-colour.
Experts said it looked to have been made by generative adversarial networks, a type of artificial intelligence with duelling computer programmes that can generate shockingly good imitations of human faces.
US lawmakers held their first hearing devoted to the threat of artificially generated imagery on Thursday.
The British, French and German governments have warned that thousands of people had been contacted by foreign spies over LinkedIn in recent years. LinkedIn told AP that it is fighting the problem and has deleted thousands of fake accounts so far this year.