The security code also can sometimes be skipped. This varies from region to region, but in the US the credit card companies do not actually require a security code match for card not present transactions. The merchant can supply the code, and if so, the credit card processing system will report back on whether or not it matched, but it is up to the merchant to decide whether or not that should disallow completing the transaction.
Similar for customer address, by the way. The merchant can supply it and ask whether it matches, but whether or not a mismatch disallows the purchase is up to the merchant.
At this point, he had not charged my card. I told him that if he did charge my card, I would file a chargeback. He charged it, I charged back, waited 2 months, and got a letter saying the chargeback was finalized and my refund was no longer "pending". Idiot cost himself probably 6% of the transaction both running it and paying for processing the refund, plus got a bad mark with his merchant account. He did all of this because he thought my transaction was fraud since the billing and shipping address didn't match (yet he refused to cancel it and charged it anyway).
Gas stations also verify billing zip.
2) Security codes are always 3 digits. I don't know why you think 4? 9999 => 999 combinations.
However, it's easy to tell the difference between an AMEX and a VISA/MC from the card number alone.
The 4 digit code on the front is their CID, asked for by most merchants.
I don't recall ever being asked for the three-digit code on the back (like I am with most VISA/MasterCard credit cards). It's always the four-digit one on the front.
Some discussion, which doesn't shed a whole lot of light though: https://insideflyer.com/forums/threads/what-is-the-3-digit-c...
Yeah, that's not a big number, even manually, much less for a hacker.
I went to school for two months and the TV in my dorm room had been locked down to a few channels by some parental security crap, presumably by a previous occupant. With nothing better to do, I manually went through codes until I found the right one and unlocked it to open up more channels for myself.
It was only intimidating when I was entering random guesses at first. As soon as I decided to just methodically go through all possible combinations, it only took me something like two or three days of doing this when I wasn't in class and was watching TV anyway.
I am so glad I never tried to use BS like that with my own kids.
But how many false attempts do you have to make before the suspicious activity is picked up? At one a day you probably aren't going to get it right.
http://m.wolframalpha.com/input/?i=count+of+permutations+of+...
You're correct that almost all don't have three identical digits, but that's just because there's only 10 of them -
000, 111, 222, 333, 444, 555, 666, 777, 888, 999
10/1000 = 1%
I doubt they would make up rules for determining the cvv, as it would only improve security until bad actors could determine the rules - then it would hinder security as there would be less entropy in the selection space.
Maybe you could abuse this to create a lot of netflix accounts, but you aren't really going to be able to buy anything with just the PAN/cvv/expiry.
It's a website that specializes in letting criminals convert credit card details (PAN/cvv/expiry) into bitcoin while exposing them to minimal risk.
There are very real ways to commit such fraud.
I'm sure it may seem so for someone who's really never dealt with fraud, but it's definitely not as easy as just signing up to amazon and making an order.
If you tried to use UK cards gained from doing this, I assure you, not a single one of your orders would ever ship.
You'd just be wasting your time getting all your drop addresses (or purse customer addresses) blacklisted.
Absolute statements like this are so hard to back up.
For instance, if you live in Cuba, Iran, Syria, North Korea, or Syria, Amazon.com gift cards are worthless.
I know I received some AmericanEagle gift cards as a promotion recently, and unloaded them for less than face value just because I had absolutely no need/want to use them.
Many credit card rewards programs offer Amazon gift cards as a redemption option. The points:value ratio on these is generally significantly better than the ratio on cash rebates, even when you consider the hit taken on sites like purse.
e.g. 10,000 points might be redeemable for $100 in Amazon GC, but only $50 in cash, so even if you get the GC and sell them for $85, you still do better than if you had straight redeemed it for USD.
Why not just buy magnetic stripe dumps for a couple of $ each online? Significantly better risk/reward ratio.
Once an attacker has a valid credit card number and expiration date, there are only 10⁴ = 10,000 four-digit security codes possible, which the attacker tries with parallel requests to hundreds of websites. Each website gives the attacker at least a few tries to enter valid credit card information.
Worst case, it takes only 10,000 parallel requests to guess the correct security code. Worst case.
I don't know whether to cringe or laugh at this.