5 Tools to Test and Detect Fake or Counterfeit USB Flash Drives
There are plenty of fake and counterfeit products around and the world of computers is not exempt. In recent years one area has become more prone to this than any other, and that is flash memory storage. Devices such as USB flash drives, SD/CF cards and even SSD drives have been affected by this problem. Counterfeit USB flash drives seem to be the most common though, there’s so many different types, capacities and speeds that it’s easy to hide them among all the real products.
You may think this problem only affects places like eBay but even Amazon and other legitimate retailers have been caught out too. This is why it’s a good idea to check any flash device you purchase is the product you paid for. Making sure the serial or code number on the stick is legitimate is one way, another is making sure the drive is the size advertised because most fake drives have a lower real capacity than listed by using smaller and much cheaper memory chips. The drive may even be reported as the right size in windows.
Software developers are also aware of this and some have written tools to help you identify if a drive is smaller than you expect and is therefore likely to be counterfeit. Here we have listed 5 for you to try that are designed to check for fake size drives.
1. H2testwFor several years H2testw has been known as the go-to tool for checking memory based flash drives to see if they are the correct capacity. The problem is it was developed back in 2008 when flash based media was smaller in size. A scan with H2testw can run into several hours or even days on newer large capacity drives, especially if they also have slow write speeds. However, it could be a price worth paying.
The method used in H2testw is very slow but is still one of the most thorough and reliable ways to scan the drive for a fake capacity. It isn’t a fully destructive test because it only checks the free space on the drive, but the best way is to use H2testw on a cleanly formatted device, that way it will be checked completely.
H2testw works by writing large 1GB files to the free space and then reading them back. If the read data isn’t the same as what was written, there’s a possible issue. You can also select a custom amount of data to write which is useful if you suspect your drive might be a specific capacity. For instance, if you think the drive is only 4GB and not the full advertised 32GB, a test can be run on 6GB of data.
After it’s done the software leaves the test files on the media, you can delete them or verify them again. If you have the time and want a very thorough test, try H2testw. It defaults to German language but you can easily change it in the GUI.
2. FakeFlashTest
The FakeFlashTest utility is from the developer of the RMPrepUSB multipurpose USB tool. One component of RMPrepUSB is a quick test to check your drive and its real capacity, this is an extended and enhanced version of that and is released as a standalone executable. Unlike some other similar tools, FakeFlashTest is not that old so includes optimizations and methods better suited for modern flash media.
FakeFlashTest tries to fix the main issue with H2testw which is the long time it takes for the process to complete on larger or slower flash drives. The first test you can run is the same quick test found in RMPrepUSB itself. This writes and reads 512 bytes of data at set intervals across the drive and so finishes in less time. It starts at the end of the drive first so should pick up an undersized flash drive pretty quickly.
The second test is similar to H2testw and writes to the free space on the drive then reads it back to verify. The process has been optimized to hopefully complete the task much quicker than H2testw. The written files are read back at intervals of 3GB, 5GB, 9GB and 17GB. It means that if your fake drive really has a 4GB capacity, you should know after the 5GB read test and won’t need to go any further.
Do note that the the quick test is destructive meaning anything on the drive will be overwritten, so make sure your files are backed up. The slower test is not meant to be destructive but can still corrupt your files if they are on a bad area of the drive, so it’s highly advisable to backup first either way.
3. Flash Drive/Card Tester
Flash Drive/Card Tester is listed by its developer as a generic tool for testing flash drives or SD/CF cards but is especially useful for detecting counterfeit drives with fake capacity. It works in a similar way to H2testw by writing data to the device, reading it back and then comparing the two for differences. Any errors indicate a problem with the drive.
To run a full test select your flash drive from the drop down and choose the test type “write, read and compare”, then start the test. If you don’t have the time to run a full test on a large or slow drive, the data can be written to the drive now and compared later on using the separate test types of Write and then Read. Flash Drive/Card Tester officially comes as a setup installer but because it’s only two files, we’ve zipped them up to create a portable version.
Download Flash Drive/Card Tester | Flash Drive/Card Tester Portable
4. Quick Disk Test
This tool is made in Java so it can run on other operating systems like Mac and Linux as well as Windows. It does obviously mean you need Java installed on your system. To run Quick Disk Test, you may have to right click on the .Jar file and select Open or Open with > “Java(TM) Java Platform Binary” as double click might not work.
Click the location button at the top to select a drive. How much data you want to write is up to you. For instance, you can choose to 30% fill the drive or fill it with a specific amount of data. Alternatively, use the leave free option to do the opposite. Fake drives are typically something like 2GB, 4GB, 8GB or 16GB so you could start with a percentage that will cover some or all of those capacities.
Data already on the drive is not overwritten but new data is added to fill to the selected amount. A useful function is being able to stop the process while writing data to the drive, restart the program later and continue filling where it left off. For some obscure reason, the drop down capacity menus go up to Yottabytes which you’ll never need. For those that don’t know, one Yottabyte is one Trillion Terrabytes!
5. ChipGenius
The programs listed above all work in the same way which is to physically write data onto the disk and then read it back to see if the data is correct or corrupt. ChipGenius is completely different and actually doesn’t touch the data on the drive at all. Instead, it reads the information from the flash memory chip inside the drive to see what it is and what it’s true capacity should be.
Run the program and look for the information about the flash chip inside your device, a line will give the vendor and model number of the chip and hopefully its true capacity. If capacity is not shown, copy the other data on the line (Ctrl+C) and enter it into a search engine, which might offer some more information. Right click in the window to copy all the shown data to the clipboard.
Note: Be aware that ChipGenius generates a number of false positives with online virus scanners like VirusTotal. Don’t download the program if this makes you uncomfortable.
Download ChipGenius (Russian site) Direct Download of ChipGenius (Password = usbdev.ru)
Final Note: Apart from ChipGenius, all other tools write data to the drive. Whether the tests are meant to be destructive or not, it is highly recommended to backup anything still on the drive. Data has been known to get destroyed when drives have real errors on them or capacity issues.
You might also like:
5 Free Tools to Check and Test USB Flash Drives
8 Free Tools to Test Read and Write Speed of USB Flash Drives
5 Tools To Encrypt and Protect your Data on USB Flash Drives
7 Portable Tools to Make a Full Image Backup of USB Drives
5 Tools to Test CD or DVD Readability by Running a Surface Scan and File Test
For macOS users who can’t run the Windows programs recommended above, if you’re comfortable using the command line, I recommend the “F3” (Fight Flash Fraud) suite of tools. They are free and open source: https://github.com/AltraMayor/f3 .
Of F3’s five tools, only “f3write” and “f3read” work natively on macOS, but that’s all you need to check a drive’s true capacity. Example of usage:
# install with Homebrew
brew install f3
# write test files to the drive
f3write /Volumes/my-new-suspicious-drive/
# confirm that all test files are the same when read back
f3read /Volumes/my-new-suspicious-drive/
I bought a 256GB sandisk extreme pro with 170MBps write and 90MBps read…about 10US DOLLARS on shoppe.ph… using its
Card adapter then i full format it for NTFS on win10 dell i7 e6410 , takes 6hours .. then i SUCCESSFULLY copied more than 190GB (clicking PROPERTIES) on it in almost 6hours at 10MBps TOP SPEED in task manager speed…. QUESTION = is it a fake or is it a low quality ..please help.
Your data should not be corrupt. Review items uploaded from every 30 minutes mark and check if all are readable. Make sure you open the file/image/video/audio to fully ensure it’s not corrupt.
In regard to the programs that write/read data to determine the drives true size, if the drive was say 64GB but faked to say 32GB, would an encrypted hidden 32GB volume still be detectable with this method? Would it throw errors? or simply not even attempt to read the rest as it states its only 32GB? Open to anyone’s hypothesis!
Obviously any program reading things at a flash chip level will defeat this, but I’m still curious…
The latter, like if you format a hard drive partition smaller than the full capacity, the software writing to it doesn’t start second-guessing the true capacity, it operates at a level (or three) above that. In the same situation with a very suspicious and dodgy disk.
My problem is I need Linux not Windows software, plus chipgenius is suspicious. I mean, it can put BadUSB on your device, if it’s already operating at that level, face it…
As can whatever dodgy Pfsion chip flasher.
People are obviously DESPERATE for official software from the manufacturers, for this purpose. Where are the worthless manufacturers when you need them? It’s not like they are going to lose out, is it?
Nobody faking a usb drive will make it appear smaller than it truly is. There is no point. If the drive was truly 64Gb, then they would doctor the chip to ‘apparently’ be 128GB or more. As a side issue, many (many) years ago in the old days of DOS, when drives were 10, 15 and 25Mb Yep – Mb!) a colleague wrote a small program to check disk sizes. First confirm a small area is ok, then write a block and check read by starting at a high address, if the read failed, he halved the address and tried again. he could find the true size very quickly.
Any recommendations that will run on MacOS?
ChipGenius worked for me, it told me my new 500GB USB stick was only 16GB
There’s an easer way to tell! If it was under 120 bucks then its definitely fake lol
Can i change the capacity back to originals,,?
No, the code that tells your computer the size of the drive is injected at the time of manufacture. However, you CAN use a formatting tool to create a partition on the drive which is of the correct size and simply use that instead ^^
I downloaded and tried to put ChipGenius on my Windows 10 system. The password seems correct but the .exe main file shows malware and is detected by my antivirus (Webroot SecureAnyWhere). Fortunately it gets detected before it does any damage and before it gets written to my hard drive. I got one version via the link on this website and the same version from SoftPedia. So after 2 attempts using files from 2 sources, I am reasonably certain that this program does contain a virus. I do not want to find out how nasty as that would entail having to remove it after it does damage. I will use H2testw until I can find something better and also free of malware.
We literally tell you in the article this program generates false positives and not to use it if that makes you feel uncomfortable. It does not contain viruses and has been around for almost 10 years. That’s plenty of time for anything malicious to have been found, which to my knowledge, nothing ever has.
“Flash Drive/Card Tester” will erase all the data on your SD card, and takes hours to scan. This would have been nice to know in advance. All we need are counterfeit detectors, or perhaps just to assume that everything from Asia is counterfeit.
The tool will tell you it will erase all data before you attempt to run a scan, so you are told in advance. Although we don’t mention it here, you can’t start a write scan without knowing that.
How long it will take obviously depends on the size and speed of the flash drive and your system.
Hello,
Is there a tool which do the test and show serial number in same window ?
That way I can ask seller (person not company) to run the test and send me screenshot and if everything is OK, I just check if serial is same…
And it should also work with new flashes (like 256GB or more).
Thanks
nirsoft.net/utils/usb_devices_view.html
Is there a tool for not only testing but reformatting the fake drive to its true capacity? Something that rewrites CRC or creates a true-size partition?
I have read somewhere that you could use a partition manager to simply create 2 partitions. 1 Partition with the true size, and the other with the fake “overhead”. Now you could write only to partition 1 and leave partition 2 alone. This should be a workaround to still use that cheap Chinese Chip :-)
There is the HP USB Disk Format Tool and I have used it to format an 8Gb USB drive but I don’t know if it also detects the true capacity. It is free so you can check it out. It did a good job of formatting but I had already repartitioned the drive before I tried it.
ChipGenius would be the best but unfortunately it doesn’t appear to work on SD Cards plugged into a USB adapter.
I recently purchased a Kingston Hyperx Savage 512GB Flash Drive, and I’ve verified it’s legit with Kingston Customer Care, via the Serial Number, but I thought it would be nice to have a tool to verify it’s true capacity myself. So far I’ve been unable to locate any reliable software, that will actually work with these higher capacity drives. It fails on nearly everyone of the recommended applications, either immediately, or shortly after running the recommended app. Is there no reliable tool out there, that will test the larger sized flash drive memory sticks?
Ray, this blog is a year old. Time for a refresh
I first use SD Insight to check for manufacture’s logo — if none, invariably fake.
Then I use h2testw to verify size.
Looks like that is an app for Android devices only. Not for PC. My phone has no micro sd slot.
please update with a mirror of chipgenius. the download site is not working.
I use ChipGenius to get a fast response and then check with some images.
I copy many images to the drive and then some images start scrumbling.
TEST.BAT (Batch file for WIN10):
FOR /L %%A IN (1,1,9999) DO (
COPY Image_20000.bmp F:\%%A.bmp
TIMEOUT 60
)
All I get is Unknown device, nothing else.
FakeFlashTest always seems to crash during the reading portion of the test, at which point is dependent on the fake flash drive in question I think, had it stop responding at 95% complete, 90% and latest at 30%. Let the window stay around for a couple hours just in case, but it seems once it goes Not Responding it stays that way. And it takes 4hrs or so just to get the point where it crashes. How has anyone progressed to complete the test? Can the test somehow be resumed if the task needs to be killed? Is 2TB just beyond this test applications capability?
2TB flash – then it’s obviously fake unless you paid a huge amount of $ for it!
FFT fills memory from the top downwards. Most fake drives have no memory at the top and the real memory is at the bottom. So if FFT starts to get very slow when reaching 90%, it just means it is trying to write to the ‘real’ memory in the flash device. If Windows gets errors, then it will timeout and retry on every write operation and this can take many many hours if testing the bottom 200GB!
Use ChipGenius to try to find what memory chips it actually has.
How long does H2TESTW take?
HAve a supposed 1TB flash drive…It is taking over 100 hrs for H2 to complete the test…There has to be a more efficient way to check for capacity…
Yes, use FakeFlashTest’s Quick Size Test. But if also want to test the flash memory quality, there’s no way to speed it up.
Beware of ChipGenious. VirusTotal and numerous other sites list it as malware that installs a backdoor.
I’ve seen no evidence that the results at places like VirusTotal are anything other than false positives. It’s been the same way for years.
Anybody can create a simple program with just a “Hello world” message box and produce more detections in VirusTotal than ChipGenius. That’s how unreliable those services can be these days.
Regarding the malware triggers for ChipGenius, if you look at the actual details of a VirusTotal scan, you will see that there are multiple generic detections based on Heuristics, but not really any specifics.
This means the software does something the antivirus vendor considers suspicious or dangerous, not that it’s actually malware.
False positives are very common with software that does certain low-level operations such as manipulating device drivers or opening network ports.
They also often happen when software is created using certain tools that also happen to be used by malware frequently. The AutoIt3 script compiler is a valuable, flexible and important administration tool, but because it has been used maliciously in the past, programs compiled with it often get flagged as malware.
UPX compression is a useful tool, but it is also often used by malware authors, so innocent programs that use it sometimes trigger false positives.
It’s right and reasonable to be suspicious of any software that triggers a malware response. There have been cases where real legitimate software was infected with malware, so it’s not impossible, but if the program is well-known and has been around for a while, and other people say they trust it, you can probably assume it’s a false positive.
Always get software from the original sources whenever possible. Don’t download software based on results of a Google (or other search engine) search, as there are often fake or misleading links.
Look at the reputation of the program and how long it’s been around.
Yes ChipGenius is not detected as malware by bitdefender but as malware by other antivirus (Smadav). It checks total capacity very fast (almost instantaneously) on fake USB. On Dual USB Sandisk 3.0 128 BG (OTG) original it ,ChipGenius couldn’t detect total capacity in normal detection but it recommended “forced detection”. But I didn’t excecute it to avoid damage to my files. I bought Flashdisk 3.0 Toshiba 64 GB but total capacity according to ChipGenius is only 512 MB. Description: [D:]USB Mass Storage Device(USB2.0 Flash Disk)
Device Type: Mass Storage Device
Protocal Version: USB 2.00
Current Speed: High Speed
Max Current: 100mA
USB Device ID: VID = 1221 PID = 3234
Serial Number: 2016112614400062
Device Vendor: USB2.0
Device Name: Flash Disk
Device Revision: 0000
Manufacturer: USB2.0
Product Model: Flash Disk
Product Revision: 2.60
Controller Vendor: Micov
Controller Part-Number: MW8209(MXT6208E)
Flash ID code: 2CBC9066 – Micron MT29F4G16ABBEA – 1CE/??? [SLC-4K] -> Total Capacity = 512MB
Hint: : Please exit this program and RE-PLUG your USB Flash Drive before you can operate it!
Result of test on original Dual USB Sandisk 3.0 128 BG (OTG):
Description: [D:]USB Mass Storage Device(SanDisk Ultra)
Device Type: Mass Storage Device
Protocal Version: USB 2.10 <- Hint: This device can run faster when plugged to a USB3.0 port
Current Speed: High Speed
Max Current: 224mA
USB Device ID: VID = 0781 PID = 5590
Serial Number: 4C531001621217117105
Device Vendor: SanDisk
Device Name: Ultra
Device Revision: 0100
Manufacturer: SanDisk
Product Model: Ultra
Product Revision: 1.00
Controller Part-Number: Unknown
Beware of fakes Transcend Jetflash 700 on eBay.
here the result (256GB):
h2testw :
The media is likely to be defective.
15.1 GByte OK (31771168 sectors)
234.8 GByte DATA LOST (492488160 sectors)
Details:0 KByte overwritten (0 sectors)
0 KByte slightly changed ( Total Capacity = 16GB
Tools on web: dl.mydigit.net/special/up/alcor.html
Possible Flash Part-Number
—————————-
Unknown
Flash ID mapping table
—————————-
[Channel 0] [Channel 1]
AD3A14AB424A ——–
——– ——–
——– ——–
——– ——–
FAKEFLASHTEST v1.1.1 [SSi]
DRIVE 1 – 249.0GiB Generic Flash Disk
FFT – Quick Size Test (destructive)
D: (no label) DRIVE 1 – 249.0GiB Generic Flash Disk
Writing marker blocks to drive 1
5% complete – 1 min 35 sec remaining
10% complete – 1 min 21 sec remaining
15% complete – 1 min 20 sec remaining
20% complete – 1 min 12 sec remaining
25% complete – 1 min 9 sec remaining
30% complete – 1 min 3 sec remaining
35% complete – 1 min 0 sec remaining
40% complete – 0 min 54 sec remaining
45% complete – 0 min 51 sec remaining
50% complete – 0 min 45 sec remaining
55% complete – 0 min 41 sec remaining
60% complete – 0 min 36 sec remaining
65% complete – 0 min 32 sec remaining
70% complete – 0 min 27 sec remaining
75% complete – 0 min 23 sec remaining
80% complete – 0 min 18 sec remaining
85% complete – 0 min 14 sec remaining
90% complete – 0 min 9 sec remaining
95% complete – 0 min 15 sec remaining
100% complete – 0 min 1 sec remaining
Reading back marker blocks…
5% complete – 1 min 54 sec remaining
10% complete – 1 min 48 sec remaining
15% complete – 1 min 42 sec remaining
20% complete – 1 min 36 sec remaining
25% complete – 1 min 30 sec remaining
30% complete – 1 min 24 sec remaining
35% complete – 1 min 18 sec remaining
40% complete – 1 min 11 sec remaining
45% complete – 1 min 5 sec remaining
50% complete – 0 min 59 sec remaining
55% complete – 0 min 54 sec remaining
60% complete – 0 min 48 sec remaining
65% complete – 0 min 42 sec remaining
70% complete – 0 min 36 sec remaining
75% complete – 0 min 30 sec remaining
80% complete – 0 min 24 sec remaining
85% complete – 0 min 18 sec remaining
90% complete – 0 min 12 sec remaining
95% complete – 0 min 6 sec remaining
Memory tested in blocks of 25600 sectors.
BAD MEMORY from sector 31814074 (15,534.0MiB) to sector 524281274 (255,996.0Mib)
WARNING: no memory detected at one or more locations.
Test took 1252 seconds.
*** FAILED ***
DEVICE HAS DUPLICATE OR BAD BLOCKS!
Recommended maximum usable partition size: 15,521.0Mib (approx. Last good Sector=31814074)
H2testw gives me correct results: good drives are either 100% good or a trivial 11K bad, and a known fake drive that lost data was 2G good/30G bad.
FakeFlashTest didn’t work for me. It said all my flash drives are bad, even the ones that I know are good.
There is another,, open source, there is a git,, F3
F3 probe 6.0
Copyright (C) 2010 Digirati Internet LTDA.
Runs on linux,, relativly fast
Last run on a 64G evo+
Probe finished, recovering blocks… Done
Good news: The device `/dev/sdb’ is the real thing
Device geometry:
*Usable* size: 59.69 GB (125171712 blocks)
Announced size: 59.69 GB (125171712 blocks)
Module: 64.00 GB (2^36 Bytes)
Approximate cache size: 0.00 Byte (0 blocks), need-reset=no
Physical block size: 512.00 Byte (2^9 Bytes)
Probe time: 8’26”
I tried all 4 and they do check the size but -NONE- of them “Detect Fake or Counterfeit Flash Drives”.
.
A fake or counterfeit flash drive says it has xx amount of storage but actually contains much less, that’s the reason the fake exists. That is exactly what these tools tell you, whether you’ve got the storage you paid for or a fake capacity.
It would be highly unlikely to get a fake flash drive with the full amount of storage, it wouldn’t be worth the fake manufacturers time.
I am using H2TestW for long time, actually it only check the capacity, writing and reading from disk.
May be you have all good quality cards/flashes.
If you insert Fake card and check with H2TestW, the moment when it can’t write/read the area, its screen will be RED and give you the final result at end of check.
Chipgenius reported as malware/virus by Microsoft Security Suite. October 2016.
False positive…
Hi, This may sound counter intuitive, but I would like to do the opposite and reduce the reported size of an SD card. I have an old synthesizer that was only designed to access SCSI hard drives of 80MB or less. Recently I purchased a SD / SCSI adapter and when the synth tries to format an 8GB SD Card, for example, in the adapter, the synth complains that the capacity of the “hard drive” is invalid. The method the counterfeiters use presumably is to take the MBR partition table of a larger card and write it to the MBR of a smaller card, but this would not work for the synthesizer, as the disk format is proprietary and there are no partitions. Is there a way to tell the SD card at a lower level that it has fewer cylinders etc.? Failing that I am left with reading / writing disk images within Windows / Linux, which works, but can be cumbersome and risky!
I dont know of any way to alter the reported capacity of an SD card.
You can use RMPrepUSB to write disk images. In it’s default setting, it will only list USB devices.
realy late comment:
you can try to make 2 partitions on the sd card(dont know good software, but linux is always good)
A good Windows Software is the MiniTool Partition Wizard. Just create the first partition the size you want and leave the rest unalocated.
This is also a good method of using fake capacity drives.
Find the actual number of sectors using h2testw or F3probe then put this good area into one partition and leave the fake area unallocated.
Most of the cheap flash drives on eBay are 8GB ones faked to look much bigger.
Hi Andy,
Maybe your problem is resolved in the meantime, but you can try this for your old synthesizer: buy a 2 GB SD card, or less. In those time, the greater capacity addressable was 2 GB. Then SDHC (High Capacity) was created, giving access to 4 GB and more of storage. Older systems don’t works with SDHC, so stay with 2 GB or less for your older synth.
Maybe you can still find some old 64MB CF Cards out there? With adaptors they should behave like old Hard drives (I have thrown mine out only 2 years ago, nostalgic days when one considered 64MB Card HUMONGOUS space (Was actually taken up pretty quick by my Canon S40, 4MP cam :-)
H2testw made my 64GB micro sd card usable space from 59.6 GB to 58.2 GB. Can I restore capacity that I had before using this program?
I have ran this program many times, there is a file from the program still on there that you must not be seeing. The best way is to back everything up and then format the card. This will fix your problem. BUT BE SURE NOTHING IS ON THERE, for which you will lose it if you don’t.
reformat the pendrive with original filesytem.. for example…. if it was fat32 and now its is NTFS change it back to fat32
remeber you wont be able to save files over 4 GB on fat32
Thanks 4 this info I’m a bit of a tech-head and a bit of a perfectionist. I don’t mind waiting as long as I get accurate information. Will probably download 50% of these programs (when I get my comp back) to TOTALLY make sure I’m getting what I paid 4. Let U know on all programs.
guys the h2testw doesnt work on unformatted sd card but the if the sd card is not formatted it cannot run and i cannot know exact size and i cant fix it
Chipgenius has a virus, per mcafee….
False positive, McAfee’s famous for false positives…
Same for Panda, which don’t have a bad reputation for false positives
Thanks! But it should be noted that ChipGenius is only useful for USB flash drives, not SD flash cards.
I really thank you!
Gergely
Nice Post. thanks
thanks ……… makes me more comfortable knowing i have a real 16gb memory (speacially since i bought it from ebay!)
thanks for the information. If it wasn’t for you I would have got my self a fake.
Thank you so much for this.
Thanks for the tips .. is really a good one
thanks for the post ray……now i can always be sure about my pd
Very useful, thanks Raymond
Thanks for this, as always.