After Breach, Companies Warn of E-Mail Fraud

By MIGUEL HELFT
NYT

SAN FRANCISCO — Security experts said Monday that millions of people were at increased risk of e-mail swindles after a giant security breach at an online marketing firm.

The breach exposed the names and e-mail addresses of customers of some of the nation’s largest companies, including JPMorgan Chase, Citibank, Target and Walgreens.

While the number of people affected is unknown, security experts say that based on the businesses involved, the breach may be among the largest ever. And it could lead to a surge in phishing attacks — e-mails that purport to be from a legitimate business but are intended to steal information like account numbers or passwords.

“It is clearly a massive hemorrhage,” said Michael Kleeman, a network security expert at the University of California, San Diego.

(More here.)