The security breach that hit Target Corp. during the crucial holiday season seemed to be part of a broader and highly sophisticated scam that affected several retailers, says a report published by a global cyber intelligence firm that works with the Secret Service and the Department of Homeland Security.
The report, released Thursday by iSight Partners of Dallas, offers more insight into the breach at Target, which affected 40 million credit and debit card accounts and has stolen the personal information including email addresses and names of as many as 70 million customers.
The report said that a malicious software that infiltrated the point of sale system at the registers was ‘‘almost certainly derived’’ from BlackPOS, a crude but effective software product.
It said that starting in June, iSight started seeing the malicious software codes on the black market. Full story for BostonGlobe.com subscribers.