It's shockingly easy to make a counterfeit SD card or USB drive. Shoot, it's even easy to make a counterfeit SSD. All a scammer needs to do is take a few gigabytes of cheap flash storage, write some bogus firmware to the controller, and Windows will be none the wiser that your 256GB USB drive only has 4GB of real capacity — and probably plenty of other problems when it comes to performance and data integrity.

Despite how easy it is to make counterfeit storage, it's anything but easy to tell if you're using a counterfeit drive. And usually by the time you find out, your data is already at risk. Thankfully, there are a handful of tools you can use before you start using an SD card or USB drive proper to make sure everything is above board.

Before getting into the tools, you only need to check the legitimacy of your storage if you bought it from somewhere like eBay or a third-party seller on Amazon from an unknown brand. I've never heard of big-box retailers selling fake drives, at least. A little common sense goes a long way, too. If you see a price that's too good to be true, there's a good chance it is.

4 Check the basics with CrystalDiskInfo

The lowest hanging fruit

First up is CrystalDiskInfo. You can see some basic details about your drive within Windows, but CrystalDiskInfo puts everything in one spot. Here, you can see the transfer mode, the reported capacity, the firmware number, the serial number, total reads and writes, and so much more. This is the low-hanging fruit of verifying that you have a legit drive. If you pop into CrystalDiskInfo and something doesn't match up, you have a fake drive, and one that the scammer didn't even try particularly hard to hide.

CrystalDiskInfo is a good tool to have on your PC regardless, mainly for quickly checking SMART values, so it's a good place to start if you want to quickly check if a drive is legit. It's very easy for a scammer to undermine what CrystalDiskInfo is reporting, though. Ultimately, this tool reports data from the drive itself, so if your drive has bunk firmware, it might report details that look completely real even if they aren't. A couple of good places to focus in on are the firmware and serial number. You can search for these and hopefully get a better idea if your drive is real or not.

Still, you should expect everything to look above board in CrystalDiskInfo. The real killers start to show up when you're actually writing and reading data from the drive.

3 Run a benchmark to confirm performance

Where things start to fall apart

Counterfeit drives hit you on two fronts. The performance isn't at the level of the product it's trying to emulate, and you usually have much less capacity than what's reported in your OS. Performance is the first place to check, though, not only so you can spot if your drive is counterfeit, but also so you can make sure that you didn't pick up a lemon. Even among legit SD cards and USB drives, some percentage of them will be duds. A quick benchmark will help you identify both a dud and a counterfeit, so it's a good test to run.

There are a ton of benchmarks available, but CrystalDiskMark is somewhat of a platonic ideal for performance. It gives you some basic performance numbers for reads and writes across both sequential and random workloads. Most SD cards and USB drives have at least a basic number for reads and writes printed on the box, and in the case of SD cards, there are even certain standards they need to reach to earn different classifications. The results don't need to be bang on the money, but you should see sequential reads and writes near what the package says.

2 Spot test with ValiDrive

A quick way to confirm capacity

Now, it's time to test capacity, which is more difficult than it seems. If you have a counterfeit, you can't just write a bunch of data onto it. In most cases, the files you add will still show up within File Explorer, but the actual data isn't written to any flash storage. If you try to open those files, you'll get an error. It's difficult to test capacity because it looks like everything is working correctly. And, if you have a massive SD card or USB drive, trying to write hundreds of gigs of data just to confirm the drive is real isn't an easy task.

That's where ValiDrive comes in. It's a spot-checking utility that's fast and can easily identify if a drive is fake. Instead of writing data everywhere, ValiDrive randomly chooses different sectors and tries to read and write data to them. It chooses sectors throughout the reported capacity, and if you have a drive with a mis-advertised capacity, it's almost guaranteed that ValiDrive will spot it. Counterfeits usually have much less storage than they report — think something like 4GB for a drive that's advertised to have 256GB — so there's a good chance ValiDrive will stumble upon a bad sector quickly.

1 Confirm the capacity with h2testw

If you need to be absolutely sure

With the three tools above, you should be able to spot a fake SD card or USB drive. Scammers want you to think the product you bought is legit, but only so long as you can actually return it. At a certain point, hiding the scam is more effort than just not scamming at all. But, if you want to know with absolute certainty, beyond a shadow of a doubt, that the SD card or USB drive you purchase is real, you can use h2testw.

It's a difficult utility to find — use the link below, as the first search result in Google looks like a scam itself — but h2testw will go through the painstaking process of writing and reading data across the entire reported storage capacity. Depending on the size and speed of the drive, this can take several hours, and you'll likely need to leave your PC on, unattended, for some period of the test.

Don't be on the sour end of a scam

Fake USB drives and SD cards are everywhere, especially if you shop online. There's a good chance that big names like Samsung, SanDisk, and PNY are safe if you pick one up from a reputable source, but a quick search on Amazon will turn up dozens upon dozens of no-name drives with very low prices, and I'd reckon most of them are fake.