For the second time in roughly three months, JPMorgan Chase is scrambling to contain the fallout from a security breach of its vast computer network, according to several people with knowledge of the investigation.
JPMorgan, the nation's largest bank, recently found that hackers, with links to Italy or southern Europe, had gained entry to some of the bank's servers, these people said.
The discovery follows an attack that was uncovered in late July and suggests that it was more extensive than first thought. In that attack, hackers obtained entry to dozens of the bank's servers and reviewed information on more than one million customer accounts. Security experts briefed on the matter had said that the full extent of the July attack was not known and that it could take the bank months to discover all of the fallout.