Nude pictures of former French first lady Carla Bruni were used to break in to the computer systems of dozens of diplomats.
The shocking security breach was first discovered at the G20 summit in Paris in February 2011 and may be ongoing.
"To see naked pictures of Carla Bruni click here" said a message sent to those attending, who included finance ministers and central bank representatives.
Bruni, a former supermodel who became President Nicolas Sarkozy's third wife in 2008, was well known for taking her clothes off in her early career. This prompted many to open an attachment which turned out to be a Trojan Horse with an embedded virus, although all recipients could see were the X-rated photographs.
Once accessed, it infected the computers of senior officials as well as forwarding the offensive email on to others.
"Almost everybody who received the email took the bait," said a government source in Paris, saying that this included representatives from the Czech Republic, Portugal, Bulgaria, Hungary and Latvia.