Citigroup revealed Wednesday that hackers gained access to the account information of significantly more customers than originally thought
. In an updated news release
issued Wednesday, the nation's third-largest bank said that after completing an investigation, it concluded that 360,083 accounts were compromised in the attack, in which hackers infiltrated Citibank's online banking platform, Citi Account Online, and viewed customer account numbers and contact information, including email addresses. Additional data that would be needed to commit fraud, such as expiration dates or card security codes, was not exposed. Citigroup originally reported that 210,000 account holders were affected.