The US Secret Service has gotten involved in a possible security breach with a third-party payment processor that could compromise as many as ten million Master Cards, and potentially VISA.

A reporter first alerted about the potential breach in an online forum called Krebs On Security, a blog run by former Washington Post Reporter Brian Krebs.  At issue is what is called a third party payment processor.  Mastercard and VISA do not always directly process payments and other day to day operations, but often sublet them to third party companies who handle the processing and accounting.

  VISA and Mastercard process card information for various banks around the country who issue the cards through their institutions.  These third party operators, along with the third party data processors, are apparently the firms who could be affected.   VISA and Mastercard did not return calls or comment on the issue, all that is known is that the potential breach affects a "US based payment processor."    An independent security company is investigating the possible breach, which appears to be initially concentrated in the Eastern US, especially New York.

 While Mastercard declined to say how many accounts were potentially compromised, or what financial institutions they are notifying,  they did say their own internal data systems were NOT compromised.  Read more on this story from the Wall Street Journal.