(Washington, DC) -- The federal government is arming retailers with tech specifics on how a major data breach like the recent one at Target could happen.

Cybersecurity experts involved in preparing the confidential report released Thursday believe its contents could help merchants detect and shut down cyber attacks that may already be in progress. They say the Target hackers likely used point-of-sale malware to attack store cash register terminals. The hackers also made use of memory-parsing software to grab encrypted data as it travels through a computer's live memory in the form of plain text. The software cannot be detected by anti-virus software on Windows-based cash registers.

Retail giant Target has disclosed cyber thieves stole 40-million customer credit and debit card numbers and the personal data of 70-million additional customers during the holiday shopping season. Neiman Marcus also was a holiday cyber victim, along with at least three other national retailers.