Candy Japan hit with credit card fraud

After our first child was born two months ago, I was very much preoccupied with trying to learn the basics of infant care. 

I still had to know how much candy to order, so one day I got online for a moment to check how many new subscribers had joined during my time away.

Wow, a ton of new members are joining, hooray!

Seems they are all finding us through Google. We must have been mentioned in the media somewhere. Fantastic news! I went straight to Slack to brag about the great sales numbers.

Then I decided to look at the traffic in a bit more detail, to see where this sudden good luck was springing from.

Hmm, odd. 

The conversion ratio for organic search traffic is unnaturally high. In other words, the number of people searching for Candy Japan on Google hadn't changed, but somehow the amount of orders coming in from search had massively increased.

Having a conversion ratio over 5% for one day is a statistical anomaly. Sustaining it for the better part of the week means that something strange is going on. 

Could it be fraud?

I knew that some stores have a problem where sometimes people will buy stuff with stolen credit cards. Hey I've seen Tom Hanks chase DiCaprio in Catch Me If You Can

I was aware that a certain percentage of transactions is always fraudulent, but I had always assumed that these transactions would be mixed in with real ones. Hundred real orders there, then one fraud case dripping in here. 

Since the level of fraud I had experienced so far was at an acceptable level, I assumed everything is OK.

Everything is not OK.

What I hadn't expected was having a wave of fraud crash in suddenly with such force. 

While from Google Analytics I had noticed that a lot of sales had happened, it didn't reveal the severity of the issue. Looking at the list of transactions, I saw that thousands of payment attempts had been made with different cards during those 4 days. For each successful sale, the fraudsters had tried a dozen cards that had failed.

After starting to deal with this, I got contacted by a police officer in Ohio. To be doubly sure he really was a police officer, I called the local police directly and asked for him by name. "Thanks for calling me, let me just pull over". He was on patrol. His reason for contacting me was that someone had noticed an unexpected charge from "candy japan" on their card and had filed a police report.

I exchanged any information I had of the particular fraud incident he was investigating, but he seemed not to have much hope with the case, telling me that they just had to follow up as they'd received a report of an unknown transaction happening. I think he even said the words "this won't lead anywhere". I agree. Assuming fake IP, fake address, card number bought from someone online, what could he possibly do about it?

Easy money

I started reading a bit more about how this underworld works. Apparently these criminals are called "carders". The stolen cards originate from credit card security breaches, resulting in a big list of card numbers. These are later sold online in packs filtered to working card numbers only, which can be purchased for about $10 per valid card.

To be able to compile and sell these packs, the carders need to know which ones are valid. To do this, they will use an online store or service to place an order for the sole purpose of seeing if the charge goes through or not. 

If a store ends up as such a checking endpoint, they will see a sudden influx of a lot of fake orders. That's what was happening to me (and recently also to jsbin).

Carder uses my store to test 10 cards before they find one that works. For each attempt I pay a 0.15 transaction fee to my gateway and another $0.10 fee to subscription middleware Recurly. So even before a successful order comes in, I'm already out around three dollars.

Then they hit upon a card that works. Now the fee to charge that card is a bit higher, since money is actually moving. Our candy subscription is $25 / month, which costs me $1.76 in fees to charge (Recurly fee is $0.10 + 1.25%, gateway fee is 0.15€ + 2.75%).

Believing this to be a real transaction, I ship the product to them. Candy itself, shipping, labor etc. will cost something around $15. So now I'm out $19.76, but I received $25. What's the problem?


When the real owner of the card notices the surprising charge on their card, they will dispute it by contacting their bank or credit card company. The customer receives their money back, as they should.

The money I thought I had is taken from me and on top of that there is a 15 chargeback fee. The end result is that I lost not only the transaction fees, but also the product and labor cost and on top of that get hit with an extra penalty.

As I wasn't set up to handle these fees, I had to spend weeks just to understand what all this means and to write a bunch of glue code to export the chargeback information and convert them from gateway internal IDs to the ones understood by the Recurly gateway. Then even more code to cancel and adjust all those subscriptions to avoid charging them again or shipping any more product.

For orders which I later noticed as very likely being fraudulent, I proactively refunded them, despite having already shipped many of those orders, leading to more losses. 

Later on these shipments will likely return to sender, as the fraudsters very likely used false names and addresses, leading to more work still.


I lost weeks of productive time and thousands of dollars in money and product. DiCaprio is cool, but I will be rooting for Tom Hanks next time.

Currently I have credit cards disabled until I can integrate with a fraud detection system.

If you would like me to send you some candy, you can subscribe here. I have also released a book on running a subscription box.