Dec. 16--

Xcel Energy customers who use the company's online bill-paying service -- and do so late at night or in the early morning -- were warned over the weekend that their computers may have been hacked earlier this month.

The hackers apparently got into computers run by Network Solutions, the company that registered the domain for CheckFree, which is Xcel's vendor, and redirected Web hits to another server. A report in the Milwaukee Journal Sentinel said the hack was traced to Ukraine.

CheckFree is part of Fiserv, headquartered in Brookfield, Wis. Lori Stafford, spokesperson for Fiserv, said that the company's own computers were never breached.

"It's a pretty small subset of all the millions of users that we have," she said.

The attack occurred between 10:30 p.m., Colorado time, on Dec. 1 and 8:10 a.m. the next morning. Up-to-date virus protection programs would have warned that malicious software was coming in but without that, some kinds of viruses may have been installed on computers.

Viruses can be used to take remote actions ranging from sending out bogus e-mails for flooding other servers to scanning for personal financial information.

To have been vulnerable, Xcel customers would have had to have tried to make a payment online during those hours with a computer using the Windows operating system, seen a blank screen and not gotten a warning from a virus protection program.

CheckFree is offering free copies of McAfee's VirusScan Plus software to anyone who may have been affected. For more information, call 877-800-4864 or 800-564-9184 and choose option 1.

The company also said that it never sends out e-mails or makes phone calls asking for passwords, in order to avoid other scams.

Stafford said that the FBI is investigating the incident. ----- To see more of The Pueblo Chieftain, or to subscribe to the newspaper, go to http://www.chieftain.com. Copyright (c) 2008, The Pueblo Chieftain, Colo. Distributed by McClatchy-Tribune Information Services. For reprints, email tmsreprints@permissionsgroup.com, call 800-374-7985 or 847-635-6550, send a fax to 847-635-6968, or write to The Permissions Group Inc., 1247 Milwaukee Ave., Suite 303, Glenview, IL 60025, USA. NYSE:XEL,

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