ENGLEWOOD, Colo. - Western Union put its Web site back online Wednesday, five days after a security breach allowed hackers to steal the credit or debit card numbers of more than 15,000 customers.
The site, which allows customers to transfer money electronically using credit cards and offers other services, was accessible by midday. Spokesman Peter Ziverts said the company was confident it was secure.
''We know we've taken the most aggressive action that we could, and we believe it's safe,'' Ziverts said.
Western Union shut the site down after discovering Friday that an error by its employees left portions of the computer system unprotected. On Sunday, the company said it determined that hackers electronically copied 15,700 credit and debit card numbers belonging to people who used the site to wire money.
Ziverts said Western Union knew of no fraudulent transactions that were consummated using the stolen numbers, though he could not say whether any were attempted. The company told Visa and MasterCard on Sunday which numbers were copied, and those companies were working with banks and cardholders to avoid fraud.
''At this point, these card numbers would be extremely difficult to use'' except by the legitimate cardholders, Ziverts said. ''It could be that the end liability is zero for anyone involved.''
On the Net:
Western Union: http://www.westernunion.com/