Credit cards are vulnerable to brute force attacks

Related story and wondering if the OP may have been chasing red herrings. I recently noticed an unauthorized charge for a small amount on my credit card (something about FB/Meta). Likely someone probing the card to see if anyone would notice. I called the CC company, had them removed the charge, canceled the card and had them send me a new card (5-7 business days). With the brand new unused card (new CC number, new expiration date, new CVV), the fraudulent payments resumed (again FB/Meta). How is this possible? The reason: digital wallets. Your credit card number, etc. transfers via digital wallets even when you cancel the card. I again called the credit card company and this time, told them to cancel all the digital wallets (there were 99 of them!). There is no way to do this online. You have to speak to a human in a call center. You then have to sit through a lecture about how all your renewing payments are going to reset and you will have to re-establish them will all merchants. "Yes, I understand that. Please cancel the card and all digital wallets!" Then you have to hold for twenty minutes (why? what are they doing? manually canceling all the digital wallets?). The lesson I learned here is that canceling your credit card may not be what you think. Also recurring payments must be incredibly lucrative and canceling them must amount to a big loss in revenue. (Edited for grammar.)

Payment processors don't allow just brute forcing all card numbers a.k.a. card enumeration or card testing [1][2] and card schemes penalise merchants and payment processors heavily if they don't take measures against it [3].

1) https://stripe.com/newsroom/news/card-testing-surge

2) https://stripe.com/blog/the-ml-flywheel-how-we-continually-i...

3) https://docs.stripe.com/disputes/monitoring-programs#enumera...

If 3D secure was mandatory everywhere that would help a lot, but if I understand correctly, it’s not really used in the US and with them being so big, card issuers are largely forced to allow non 3D secure requests or their clients will be unable to use their cards for too many things.

So an enormously good anti-fraud mechanism is severely handicapped.

It’s really frustrating for most of the rest of the world.

I don’t get it, do US citizens prefer being defrauded over what is perceived as a slight inconvenience?

Even for non-victims of fraud, they still pay for the fraud as all merchants up the prices of their goods to cover fraud costs/insurance.

I once had a person that was hired by my company and then started bragging about finding a way to add stored value to gift cards. Then come to find out they were under investigation by the FBI. This was a government contractor mind you, so the biggest security guard I’ve ever seen showed up to escort them out.

Virtual credit cards have been a thing for years. I remember bank of america or Citi providing them to me 15+ years ago. If I recall it was a java app or maybe even a standalone exe. Shocked they never took off more broadly.

Robinhood absolutely nails this. Best virtual credit card system I have ever used. So seamless. Can auth a card for one time use, 24 hours, or indefinite until you cancel. Such a great UI / UX

Recently I got an sms from my bank about a suspicious transaction overseas from my wife’s card, it was literally listed as zero USD, at a time when she was not using her phone or computer.

I initially thought the sms itself was phishing, but after checking online, the sms format matched and the bank webpage ensured the feedback process will not ask for any information so we proceeded to confirm that we did not purchase anything.

The bank immediately cancelled the card and shipped a new one.

My initial thought is that the bank safety system could be overreacting, but it was likely that someone was doing exactly what is described in this article and the bank detected it earlier.

>As a consumer, I thought I was safe; when saving my credit card to a billion dollar valued european merchant, or when i purchase something from supermarket and ignore the receipt, but the reality is slightly different from that.

>I got the money back via chargeback in short time.

So as evidenced, you are protected by the fraud infrastructure. The bank ate the loss for the fraud and you were made whole. In the end, the banking system cares about fraud loss. And they are exceptionally good at finding the fraud. Making changes to the card payment system is extremely difficult, due to the vast scale of the systems, so without a very good justification that a particular change will move the needle on fraud rates, the banks will opt to not make the changes.

People should have a separate card for online payments and have just enough money on it for a payment.

I know that I am naïve :)

Back to the article: Weak point was a password that lead to another merchant not using 3D secure.

It seems from the article that bad actors have fully automated system, so (big) merchants should have handle automatic login attempts from the same ip address with different accounts. I see it from our wordfence logs that ip rotation is not so quick so it could be handled with some permanent ip blocking.

One other thing to add to the story is that the merchants can’t select what level of security they want from the credit card processor. For example, with authorize.net, you can accept the payment with the address doesn’t matter it doesn’t match.

I guess the real question here is how are they able to steal from you? Were they purchasing gift cards from a merchant with lax security?

It’s one thing to guess a number it’s another thing to get the money out of the system

Rate limiting and anomaly detection are the real gatekeepers here. A lot of "fraud prevention" is still reactive.

Another mistake:

> The data they took with the attempt of purchase is the card is still usable (not cancelled)

The payment flows should not distinguish between a nonexistent card, a cancelled card, and a valid card that needs 3D Secure. I bet the banks could even implement that without any cooperation on the part of the merchants.

At least with a credit card you have some fraud protection. Report it and the charge should be reversed. And chargebacks are possible.

With a debit card you’re playing with your own money.

Credit cards as a while use a security model from...what, the 1970s? Sure, they've patched by adding the 3-digit CVC, but really? A huge industry can't do better than that? Honestly, it's pathetic...

Some have speculated that the entire credit card system is compromised, end to end. I think the real question is why NSA didn't intervene in the early 1990s. Online commerce was just beginning, and the importance of electronic funds transfer was obvious, but the method wasn't set in stone. NSA knew about public key crypto well before the rest of us did. They could have helped set up very secure electronic payments, but chose not to for unknown reasons.

Why not debit cards too?

Oh okay, so this is why Amex launched the online card in the app that changes the Cvv2 every few minutes.

Okay but... so what? Authentication is a means, not an end. They seem to be missing that what matters at the end of the day is how much money/time/resources actually get lost, and who's on the hook for it. If that's negligible then isn't that mission accomplished? If we could live in a society where your name was enough and you didn't need a card number at all, and yet theft was still low and you still got your money back, that would be even better, not worse.

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