A recent phishing campaign targeting customers of several major U.S. banks was powered by text messages directing recipients to call hacked phone lines at Holiday Inn locations in the south. Such attacks are not new, but this one is a timely reminder that phishers increasingly are using lures blasted out via SMS as more banks turn to text messaging to communicate with customers about account activity.
The above-mentioned phishing attacks were actually a mix of scams known as “SMiShing” — phishing lures sent via SMS text message — and voice phishing or “vishing,” where consumers are directed to call a number that answers with a voice prompt spoofing the bank and instructing the caller to enter his credit card number and expiration date.
Over the past two weeks, fraudsters have been blasting out SMS messages to hundreds of thousands of mobile users in the Houston, Texas area. The messages alerted recipients about supposed problems with their bank account, urging them to call a supplied number and follow the automated voice prompts to validate or verify their credit card account information.
On Saturday, Jan. 30, I called one of the numbers that was sent out in the smishing/vishing scam — 281-866-0500 – which is the main phone line for a Holiday Inn Express in Houston. At the time, calls to the number went straight to an automated voice prompt targeting Bank of America customers:
“Thank you for calling Bank of America. A text message has been sent to inform you that your debit card has been limited due to a security issue. To reactivate, please press one now.” After pressing one, the caller is prompted to enter the last four digits of their Social Security number, and then the full card number and expiration date.
My recording of the call was garbled, but here’s a copy of a very similar voice prompt targeting Key Bank customers earlier in January that also was run off the fax line tied to a different Holiday Inn a few miles away in Houston [number: 832-237-8999], according to Numbercop, a telephony threat intelligence firm.
Holiday Inn’s corporate office did not return calls seeking comment, but the company apparently got the message because the phone lines were answering normally on Monday. A front desk clerk who answered the line on Tuesday said the hotel received over 100 complaints from people who got text messages prompting them to call the hotel’s main number during the time it was hacked.
According to Jan Volzke, Numbercop’s chief executive, these scams typically start on a Saturday afternoon and run through the weekend when targeted banks are typically closed.
“Two separate Holiday Inns getting hijacked in such short time suggests there is a larger issue at work with their telephone system provider,” he said. “That phone line is probably sitting right next to the credit card machine of the Holiday Inn. In a way this is just another retail terminal, and if they can’t secure their phone lines, maybe you shouldn’t be giving them your credit card.” Continue reading →