The cyber attack on JPMorgan which compromised the data of 73m households and businesses may have also hit nine other banks and brokerages.
According to the New York Times, who did not disclose the names of the affected financial institutions, the scale of the attack may have stretched far beyond users of Chase.com, Chase Online, JPMorganOnline or JPMorgan mobile, as had initially been reported.
The American newspaper, which cited “people briefed on the matter”, did not disclose the severity of the other intrusions, but suggested the hackers may have come from Russia.
Washington intelligence officials are reportedly “concerned” by the developments.
US Senator Richard Blumenthal has publically warned that the massive data breach represents a threat to American national security.
The unprecedented cyberattack on one of our country's largest financial institutions is the most chilling reminder to date of how vulnerable our electronic infrastructure is to attack. This is a national security issue.The financial services sector is equipped with some of the most sophisticated security software in the world. This successful breach of their systems must strengthen our nation's resolve to spend the time and resources necessary to better protect from cyber-attacks that threaten our national security, our economic well-being, the safety of our families, and the privacy of our sensitive financial information.
Last week JPMorgan, America’s biggest bank, revealed that the customer information of 83m households and businesses had been compromised by the attack initially reported in August.
The bank insisted that sensitive information such as account and social security numbers had not been affected.
JPMorgan's share price was left unscathed by the announcement, rising 2.48 per cent.