Customers of several banks and at least one credit union in southeastern Wisconsin are being targeted by 'vishing' thieves - callers who try to trick people into giving them confidential financial information over the telephone.

Citizens Bank of Mukwonago, Park Bank in Milwaukee, Burlington's First Banking Center, Maritime Savings Bank and Educators Credit Union are among area financial institutions that have reported such calls since Saturday, said Debby Bartolerio, security officer for Citizens Bank of Mukwonago. The calls are catching people off guard because they are coming on their cell phones, she said.

The automated caller leaves a message on phones in the 414 and 262 area codes claiming to be from a financial institution's security department and warning that the customer's debit card has been compromised. It then prompts customers to reveal their account information.

'They are continuing,' Bartolerio said Wednesday. 'I had a customer call me this morning saying she received one last night at 10:30.'

Bartolerio said she was unaware so far of anyone's information being used by the scammers for fraudulent activity.

'One of our customers did follow the initial instruction and press 1 and enter her debit card number. She was then asked to confirm it and starting thinking better of it and hung up and then immediately called and closed her card. So we haven't suffered any losses that we're aware of at this time, although I'm not sure we would know yet,' Bartolerio said.

The vishing scam is similar to Internet 'phishing' attacks in which thieves send out authentic-looking e-mails telling people there's been a problem with a financial account and that they should submit confidential information online to help resolve it. The 'v' in vishing stands for the word voice.

The data then is used by scammers to tap bank accounts or make online purchases. The technology-savvy thieves mask their identities and are very difficult for authorities to catch.

Bartolerio said that in the current scam, caller ID typically shows the call coming from an 'unknown' number.

'The information that I'm receiving is that it's an auto-dialer - that it's an automated voice that says your debit card or your credit union debit card has been suspended due to fraudulent activity, press 1 to reactivate your account,' Bartolerio said.

The Wisconsin Bankers Association said no bank, credit union or legitimate business would call and request that a customer verify personal information such as PINs, account and card numbers or Social Security numbers over the phone. The bankers group said people can protect themselves when they get such calls by not responding immediately, and thinking first about why the bank would need information it already has.

Customers targeted by such scams should call the financial institution at the number listed in the phone book or on their monthly statement - not at a number provided by a caller.

'Most people have just hung up, although if they thought it was a legitimate call, I'm not sure they'd be reporting it to us yet,' Bartolerio said. 'Which is why I think it's important it gets out in the media - so they do call us.'

The fraudulent calls can sound convincing and prey on people's tendency to act quickly to help resolve the issue. Two years ago over Thanksgiving weekend, a vishing campaign eventually traced to thieves in Spain placed about 40,000 calls in Manitowoc County and persuaded some customers of Manitowoc-based Bank First National to give up private data that allowed their accounts to be tapped.

Blocking vishing

No bank, credit union or legitimate business would call and request that a customer verify personal information such as PINs, account and card numbers or Social Security numbers over the phone.

People can protect themselves when they get such calls by not responding immediately.

Customers should call the financial institution at the number listed in the phone book or on their monthly statement - not at a number provided by a caller.

Source: Wisconsin Bankers Association