The head of the FBI, Robert Mueller, almost fell for a phishing attack and has been banned by his wife from banking online as a result.
The incident has prompted calls for better security education for people who bank online
Mueller told an audience in San Francisco last week that he started replying to an e-mail purporting to be from his bank. He then became suspicious and stopped.
Speaking about himself, he said, "Not long ago, the head one of our nation's domestic agencies received an e-mail purporting to be from his bank. It looked perfectly legitimate, and asked him to verify some information. He started to follow the instructions, but then realised this might not be such a good idea."
He said he was just a few clicks away from falling into an internet phishing scam.
"He definitely should have known better. I can say this with certainty, because it was me.
"After changing all our passwords, I tried to pass the incident off to my wife as a teachable moment. To which she replied: 'It is not my teachable moment. However, it is our money. No more internet banking for you!'"
Fraudsters are working harder to make e-mails look genuine. A UK Payments Administration spokeswoman said the number of phishing attacks is rising. It said there was a 26% increase in phishing attacks in the first half of this year compared to the same period last year.
The spokeswoman said fraudsters are getting smarter.
"In the past you could tell the difference between a genuine and fake email because of the spelling and grammar. But fraudsters are working harder than ever to make email look identical."