Most of us get e-mails every day from friends and family, and we never think twice that they could be phony.
But NBCLA has uncovered a growing problem, where you might get what appears to be an e-mail from someone you know, but it's really a scam to get you to wire money to a crook.
Dr. Donna Asimont of Los Angeles fell for such a scam. Last week, Asimont opened an e-mail titled "I Need Your Help." It appeared to be from her close friend, Norma, who's a minister in North Carolina.
"It never crossed my mind that it was a scam," says Asimont.
That's because the e-mail came from her friend Norma's actual Yahoo address.
In the e-mail, Rev. Norma said she was in England, had lost her wallet, and needed a loan of $2,000 to get home.
"I thought 'poor Norma.' You know, here she is stuck in this country by herself," says Asimont.
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So she followed the instructions in the e-mail, and immediately wired $2,000 via Western Union to an address in England.
But it was all a scam set up by a cybercrook.
NBCLA contacted Rev. Norma in North Carolina, who said she hadn't been to England for more than three years.
"No, I never asked anyone for money. Donna Asimont and hundreds of other people got an e-mail from me, saying I was in England and needed money," Norma said.
Norma says a cybercriminal hacked into her Yahoo e-mail account and basically took control of it.
Yahoo confirmed that was what happened, in a letter to Norma. Yahoo says Norma apparently received an e-mail infected with what's called a "worm virus." When Norma opened the infected attachment to that e-mail, the hacker was able to send out "a mass e-mail" to Norma's friends from her address, asking for money.
"It's as much a crime as robbing a bank," says Norma.
According to experts, cybercrooks are also hacking into people's Facebook accounts and asking their Facebook friends to wire money to foreign countries.
Many people who fall for these scams lose thousands of dollars. But Donna Asimont fortunately didn't.
Just after she wired that money to England, she decided to call Norma's cell phone, and her friend told her she was in North Carolina, not England. So Asimont had Western Union cancel the money order, before the cybercriminal in England had cashed it.
As for her friend Norma, who had her Yahoo account violated, she says the whole experience "makes you not want to use computers anymore, and go back to the horse and buggy days of snail mail."
So how do you protect your e-mail account from getting overtaken by a "worm virus," like what happened to Norma?
Companies like Yahoo say to make sure you have the most updated anti-virus software available on your computer.
Also, if you get an e-mail from a friend in need of money, call them first to verify their whereabouts, before sending money.