JPMorgan Chase denied knowledge of an additional security breach Thursday after the New York Times reported possible evidence of a fresh attack.

Hackers with ties to Italy or southern Europe recently gained access to some of the bank's servers, according to the Times report, which cited multiple anonymous sources.

It is unclear whether this discovery indicates a second breach or simply wider damage from the one known to have occurred this summer, the Times said.

A JPMorgan spokeswoman dismissed the suggestion of a new attack.

"We are not aware of any new attacks," the spokeswoman, Trish Wexler, told American Banker.

In June, hackers exploited a flaw in the bank's website to gain access to its internal systems. That attack went undetected for two months.