It's a boss's worst nightmare.
You return from a trip to find that hundreds of thousands of dollars has been transferred out of company accounts - apparently at your instruction.
But you have no idea what your accountant is talking about - you didn't give any instructions.
This is what happened to Carole Gratzmuller, boss of a medium-sized French company called Etna Industrie.
Her firm, which employs 50 people and has been making industrial equipment on the outskirts of Paris for nearly 75 years, was the victim of a specialised email phishing attack dubbed CEO fraud, or "fraude au president" as they call it in France.
'Confidential transaction'
"My accountant was called on Friday morning,"
she tells the BBC. "Someone said: 'You're going to get an email from the president, and she's going to give you instructions to conduct a very confidential transaction and you're going to have to respond to whatever instructions she gives you'."
