Caller ID Spoofing

What’s worse than a bad authentication system? A bad authentication system that people have learned to trust. According to the Associated Press:

In the last few years, Caller ID spoofing has become much easier. Millions of people have Internet telephone equipment that can be set to make any number appear on a Caller ID system. And several Web sites have sprung up to provide Caller ID spoofing services, eliminating the need for any special hardware. For instance, Spoofcard.com sells a virtual “calling card” for $10 that provides 60 minutes of talk time. The user dials a toll-free number, then keys in the destination number and the Caller ID number to display.

Near as anyone can tell, this is perfectly legal. (Although the FCC is investigating.)

The applications for Caller ID spoofing are not limited to fooling people. There’s real fraud that can be committed:

Lance James, chief scientist at security company Secure Science Corp., said Caller ID spoofing Web sites are used by people who buy stolen credit card numbers. They will call a service such as Western Union, setting Caller ID to appear to originate from the card holder’s home, and use the credit card number to order cash transfers that they then pick up. Exposing a similar vulnerability, Caller ID is used by credit-card companies to authenticate newly issued cards. The recipients are generally asked to call from their home phones to activate their cards.

And, of course, harmful pranks:

In one case, SWAT teams surrounded a building in New Brunswick, N.J., last year after police received a call from a woman who said she was being held hostage in an apartment. Caller ID was spoofed to appear to come from the apartment. It’s also easy to break into a cell phone voice mailbox using spoofing, because many systems are set to automatically grant entry to calls from the owner of the account. Stopping that requires setting a PIN code or password for the mailbox.

I have never been a fan of Caller ID. My phone number is configured to block Caller ID on outgoing calls. The number of phone numbers that refuse to accept my calls is growing, however.

Posted on March 3, 2006 at 7:10 AM •