Wall Street banks and financial companies vulnerable to hackers from abroad are getting a helping hand in defense from the nation's top security officials.

The National Security Agency has been sharing key intelligence about foreign hackers with financial firms to help them combat cyberattacks, according to a story published yesterday by Reuters.

Citing interviews with U.S. officials, security experts, and defense industry executives, Reuters said that the effort is based on growing concerns in the U.S. over the damage that would result from financial sabotage. Envisioning several "worst-case scenarios," government officials point to the possibility of cybercriminals hacking into a bank's network to deactivate stock trading systems, generate crashes, transfer large funds, or even turn off ATMs.

Though banks have yet to by hit by such severe attacks, they have been under fire from hackers for years. But the latest cyberattacks have become more sophisticated and coordinated, notes Reuters. That's led security experts to point the finger at countries like China as backing the hackers amid fears that foreign hackers could take down networks and destroy data run by key financial companies.

Earlier this year the NSA was part of a probe into last October's cyberattack against the Nasdaq's computer network. An initial report determined that the attack did not impact the actual trading platform or any stock trades, but it wasn't clear if other areas of the network had been accessed.

A report cited by Reuters this month said that the hackers were able to spy on top Nasdaq executives through the exchange's Directors Desk software. Speaking with Reuters this past July, Nasdaq CEO Robert Greifeld said that "as we sit here, there are people trying to slam into our system every day," and added that his organization spends almost $1 billion each year on security alone.

NSA Director Keith Alexander told Reuters that his agency is looking into expanding a program in which it shares intelligence on malware with the defense industry to also include financial firms. Though government and the private sector have both made improvements at defending their network data, Alexander said that "tremendous vulnerabilities" still remain.