Hackers ran up thousands of dollars in charges on the Coldwell Banker Bishop Realty phone lines, and now, broker Ray Pugel is alerting Rim country businesses of the intrusion.
Businesses with computer-operated or private branch exchange (PBX) phone systems are most at risk.
The hackers are able to break into the computer and PBX systems and use 10-10 long distance services to make international calls.
Calls overseas are especially high-priced, he said.
The hackers called Saudi Arabia, the Philippines, Bangladesh, India and Syria from the Coldwell Banker lines.
Pugel asked Qwest to block all 10-10 and international calls to prevent theft. They also activated security programs on their phone system.
"They (the phone companies) said this kind of fraud is quite common.
"Some companies have had bills as much as $100,000," he said.
Pugel filed a complaint with the Federal Communications Commission.
Pugel urges Rim country businesses to check their phone bills carefully and ask Congress to change the law that made this kind of fraud and theft possible.