Julie Sheridan was scanning her family cell phone bill last month when she discovered hundreds of dollars in international telephone calls on her child’s account.

Her son, a Deering High School student, hadn’t made the $500 in calls to the Dominican Republic, she discovered. He’d fallen victim to cell phone cloning or hijacking, where the identifying signature of a cell phone — which companies use to properly direct charges — is recorded, copied and used on another telephone to make free, often international, calls.

“It’s spooky to think somebody is monitoring our phones,” Sheridan said.

When Sheridan saw the bill, she immediately went to check her account online, and within a couple of minutes noticed that her daughter — at the time sitting in class at Lincoln Middle School — was supposedly making more calls to the Caribbean.

Sheridan contacted her cell phone carrier, in this case Sprint, and they confirmed the family had not made the calls, credited the account and issued a new identifying code for the phones.

The way cell phone cloning works is that relatively unsophisticated hardware is used to scan radio waves for the signal of a cell phone contacting a tower.

Cloning involves copying that signal and programming another cell phone to emit it, so any calls made by that phone are billed to the customer from whom the signal was hijacked.

“We have some teams that work pro-actively that identify when this is happening and try to intervene before any customers are affected,” said Jason Gertzen, a spokesman for Sprint.

He was unable to say how prevalent the problem is and whether some carriers are more vulnerable than others. When customers discover the problem they usually don’t call local police, but contact their carrier instead.

The problem of cloning led the federal government in 1998 to make sale of cloning equipment or software a crime, which has helped reduce the problem, according to the Federal Communications Commission. Cellular telephone companies still lose more than $150 million a year to cell phone fraud, but most of that is subscriber fraud, in which someone uses stolen personal information to open a fake cell phone account.

Still, customers should be careful, Gertzen said. They should check their bill each month for unauthorized charges and contact their carrier’s customer service staff right away if any are found.

The carrier can issue a new signature immediately so the clone will no longer function.

The problem was much more severe in the early days of cell phones, when they all relied on analog technology. But now companies typically use digital signals that can be encrypted and are difficult to copy.

However, sometimes cell phones do broadcast the old analog signal.

Sheridan was told that when roaming, a cell phone served by one carrier that is using another carrier’s tower can get bumped off the digital frequencies onto the analog frequency, making it vulnerable to cloning. She recalled that her son had complained that he wasn’t getting some messages and that friends had been unable to reach him. Sheridan wonders whether those calls may have been picked up by the clone.

It’s unclear whether Sheridan’s experience means someone in the area is scanning for cell phone signatures. Gertzen was unable to say and said he is unfamiliar with the technical aspects of cloning.

Sheridan said that in addition to scrutinizing her bill, she also plans to change the telephone setting that allows it to automatically roam onto other carrier’s towers, since that could increase the phone’s vulnerability.

It’s a small inconvenience, she said, for the corresponding peace of mind.


Staff Writer David Hench can be contacted at 791-6327 or at:

[email protected]


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