(USA TODAY/AP) -- Target says about 40 million credit and debit card accounts may have been affected by a data breach.
The chain said Thursday that the accounts may have been impacted between Nov. 27 and Dec. 15.
The Minneapolis company said it immediately told authorities and financial institutions once it became aware of the breach and that it is teaming with a third-party forensics firm to investigate the matter.
Target Corp. said that customers who made purchases at its U.S. stores during the impacted period and suspected unauthorized activity should call them at 866-852-8680.
Target has 1,797 U.S. stores and 124 in Canada.
Meanwhile the Secret Service has confirmed to USA TODAY that it is
investigating the data breach.
Secret Service will confirm it is investigating the incident at Target,"
spokesman Brian Leary said in a telephone interview Wednesday night.
"We don't have any further comment because it's an ongoing
The potential breach began around Black Friday,
the day after Thanksgiving and the busiest shopping day of the year,
according to the Krebs on Security website. The breach involves the
theft of information stored on the magnetic stripe on the backs of cards
used at nearly all of Target's stores around the country, Krebs
KrebsOnSecurity.com is the site of Brian Krebs, a national computer security expert and former Washington Post reporter.
An expert with a global
firm that helps companies respond to and mitigate breaches said while he
could not address the Target situation specifically, many companies -
large are small - are typically underprepared when they face a breach.
important is that the potential breach be addressed quickly, to help
get information out to those affected and to regulators, to bring in the
right experts to address the breach (such as forensics experts who can
stop cyber attacks) and to help preserve the public's trust in the
company, said Mike Donovan, Global Focus Group Leader for Beazley Breach
Response, headquartered in London.
"We see breaches across all
sizes of companies," said Donovan, who is based in San Francisco. "You
see the stories about the big ones in the news, but breaches are
affecting companies all across the board."
responded to its 1000th breach and the company has seen a "significant
number" of large breaches in the last four or five years, Donovan said.
It happens all the time, every day, with retailers, health care organizations, schools and other operations, he said.
"Any company that handles personal data is vulnerable," Donovan said.
The potential breach does not appear to involve
online purchases, Krebs reports. It appears the type of data stolen
would allow thieves to create counterfeit credit cards and, if pin
numbers were intercepted, would also allow thieves to withdraw cash from
ATM machines, according to Krebs.
Visa did not respond to e-mails or telephone messages left with its corporate office.
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