Hackers who breached JPMorgan Chase & Co's computer network earlier this year also tried to infiltrate other financial institutions, the Wall Street Journal reported, citing people familiar with the investigation.
Federal officials had asked financial institutions last month to check whether they had seen indications of cyberattack, the Journal said, citing the unnamed sources.
An undisclosed number of financial institutions responded that they had seen traffic from the suspect computer addresses linked to the hackers, but that they did not believe their systems had been breached, the newspaper said, quoting the sources.
Even among the many agencies investigating and responding, disagreements and unanswered questions remain about the extent of the hackers access at the US financial institutions, the newspaper said, quoting federal officials.
It is unclear which financial institutions were targeted by the hackers.