Yet several cybersecurity experts said that they believe those concerns are overblown.
"Banks are getting attacked every single day. These comments from FS-ISAC and its members indicate that this is not a major new offensive," said Dave Kennedy, chief executive officer of TrustedSEC, whose clients include several large U.S. banks.
"While we should remain diligent and active in monitoring, it doesnt appear there is a major offensive," said Kennedy.
The email said that FS-ISAC was maintaining the threat level at "guarded," noting that financial services firms continue to face a variety of threats.
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It cited recent attacks on retailers using malicious software that targets point-of-sales systems, SMS phishing campaigns targeting bank customers and a recently disclosed attack on hospital operator Community Health Systems.
The group also warned members about the potential for cyber-related activity emerging from conflicts in the Middle East and Ukraine.
"They are basically saying that the attacks they are seeing are the standard patterns. That it is business as usual," said Daniel Clemens, chief executive of cybersecurity firm PacketNinjas.