About two weeks after launching a breach investigation, Home Depot has confirmed that approximately 56 million payment cards may have been compromised as result of a malware attack on its systems.

In a press release sent to SCMagazine.com on Thursday, the retailer also said that “unique, custom-built malware” may have been present on its systems between April and September. The company added that the malware “had not been seen previously in other attacks, according to Home Depot's security partners.”

Brian Krebs, who revealed the Home Depot breach earlier this month, reported that BlackPOS malware, which was used against Target, had likely been used in the Home Depot cyber attack. Home Depot also announced Thursday that it rolled out new encryption by Voltage Security to protect card data, and that the malware had been "eliminated from its U.S. and Canadian networks."