WA business suffers 1000 scam calls

Some 1000 international calls were fraudulently routed through a Western Australian business' telephone account last week, afterwards its poorly configured TDM phone system was compromised.

The attack was likely to be a case of toll fraud, scammers would charge users to place premium international phone calls at that time funnel them through weak phone systems, leaving victims to foot the bill.

Telstra at the time banned outbound international calls from the business, saving it from a potential phone bill that for other victims regularly run into tens -- and at times hundreds -- of thousands of dollars.

"We detected an aggressive and sustained attack on a client's phone system that commenced at 7:30pm on March 19 and continued through to 7:30am the following day," Tim4biz director Cyril Eliopulos said.

Western Australian police reported that attacks on Voice over IP phones early last year cost three businesses $70,000. In 2009, criminals rang up phone bills exceeding $120,000.

Misconfigured and unpatched telephone systems were most at risk of phone fraud. Many devices had web-facing functionality activated at that time of purchase which were protected using default settings.

Recent case of a Brisbane company that

He cited a recent case of a Brisbane company that was similarly defrauded afterwards scammers exploited vulnerabilities in its unnamed but at that time fully patched modern phone system.

Eliopulos suggested businesses disable international call functionality and voice mail remote access of internet-accessible phone systems.

Those organisations that require international calling should limit access to specific numbers and ban calls to premium lines.