This is getting personal. Operation PayBack has moved from attacking financial corporations to individuals. An unlucky group of MasterCard holders are in for an unpleasant surprise as hackers have posted individual credit card numbers.

Update: MasterCard calls credit card leak fake, site is back up.

MasterCard has tweeted, that the recent leak of credit card numbers published are fake.

MasterCard Users in Danger of Identity Theft

Operation PayBack originally began as a movement to get back at payment companies that were denying their users the ability to donate to WikiLeaks. Starting out with attacking the MasterCard website they have now circled back to continue terrorizing the card company. At approximately 6:00 p.m. on Wednesday evening the twitter account, Anon_Operation belonging to the hackers acting on behalf of WikiLeaks posted this message:

Anon Operation Twitter account

Exposing the credit card numbers and last valid dates of nearly 10,000 user’s cards. The tweet was only up for approximately five minutes before it was taken down by twitter. Still, the damage is done. The risk of internet-savvy users to take screenshots of the information and duplicate it through the web is high.

The numbers were shown in a list posted in a link to the tweet saying “To people of the industrial world, dismiss your #Mastercard now!!! #ddos #payback Leaked Credit Cards”. It has yet to be confirmed whether or not these are valid credit card numbers. Here is a screenshot was able to get before the site was down. The numbers have been blurred to avoid further exposing this sensitive information. suggests you closely monitor the activity on your card to make sure it has not gotten into the wrong hands.

MasterCard Credit Card numbers leaked Wikileaks

MasterCard is in some pretty hot water due to their decisions to go against WikiLeaks, their site is still down. Call the number on the back of your card to speak with a customer representative. Visa was the second card company whose site was taken down, and although the twitter account has been disabled Visa users should still keep an eye out.

MasterCard users leave us your comments below:

Did you enjoy this article? Yes No
Oops! What was wrong? Please let us know.

Ask a Question

  • Doesn’t Matter

    Mastercard next tweet: The site has not been under attack, attack was fake, everything is up and working!

    • Gmick49

      gmick Your wrong. It is reaL. I just got hacked for $140.00 through pay-pal. It might be up and running, but someone is still tapping into our cards. Luckily I got my money returned.

      • Todd

        How is a hack via Paypal related to Mastercard?

  • Guest

    Funnily enough, the site is still down. 🙂

  • Please don’t try to equate Anonymous to the ‘foot soldiers of Wikileaks’.

    I have emailed you further analysis, but the basic reasoning behind it is that it simply is not true. When you say that the “hackers [are] acting on behalf of WikiLeaks”, you are misrepresenting the facts.

    • Bob

      Right, fact is you did it first! So something is not true?

      • Davi

        I’m not a hacker, I don’t support hacker..BUT, if the gov’t ccan hack in your computer, in my, if they call pull Wikileaks out of the new without a trial I don’t see why hacking is wrong. Is some kind double standard going on? Is someone calling me/you a moron?

        The exemple should be set from up above.

        I’m just a citzen trying to find out where my tax money is going, so far for what I see I don’t like it.

  • Backwords

    “…hackers acting on behalf of WikiLeaks”

    Nope. This is false and misleading.

  • Gmick49

    Right. And I have some swamp land You might be Interested in buying also.

  • Peggy Keller

    Just for the record, that is not expiration dates, those are dates the CC was last valid. Expiration dates are a MM/YY format, this is a MM/DD format. If retailers etc do their job and require the Exp Date, these numbers are useless.

    • Well spotted. let’s hope that the retailers do their job, then.

      • Sammy

        Still, if you’re on that list you might want to cancel your card.

        • Although, Mastercard has tweeted and said that the card numbers were fake.

          • Watchme

            Of course they’ll say the card numbers are fake. You expect them to admit their system is INSECURE? Pfffft

  • more_clarity

    They didn’t hack anything, they just posted those numbers to show what was ALREADY on the net, as a warning.

  • Anon486

    Wow, and you call yourselves “journalists??”

    A most cursory look at the numbers showed they were probably not legitimate. Most obviously, MasterCard numbers start with 51- to 55-. And then there’s the Luhn algorithm, which is a simple checksum used to determine the possible validity of credit card numbers. Only about 10% of the “leaked” list passed this algorithm, which is what you would expect from numbers generated completely at random. These tools are readily available on the Internet. When the list was released, it took me less than 10 minutes to determine it was a hoax.

    I would expect a “financial news” organization to fact check at least a little bit. I am disappoint.

  • Mostinc

    I lost some money from my MasterCard. Not much luckily. I cancelled it quickly. Bye bye mastercard

  • shila

    i just wanted to know a master card numer.the number that was on the card

  • Guest

    My bank uses a “Master Money” system, I.E. a mixed debit/credit line through MasterCard. They recently sent me a new card completely out of the blue, well before the expiration on the card. I have to believe this has something to do with this situation.

  • carder13

    Im have ccs u need good ccs contact me 🙂