A compatability list for uSD cards is available
here.
This list only shows two models of Samsung Pro that are known to be working, 16GB and 32GB models, not an 8GB PRO model as you have.
This does not mean your card is fake, just that nobody has reported a Samsung Pro UHS-1 Class 10 8GB Micro SDHC Card as working with a RPi's.
If you are concerned about a fake card, use f3 as mentioned by forest.
Alternatively, write an large file to the card, 7-7.5GB DVD ISO image (or multiple smaller images) should do, and check the source and destination MD5 hash.
The closer you get to filling up the card and then verify the file(s) are OK, the more certian that it's not a fake (but f3 is the difinitive test)...
On Windows, i use
SummerProperties to add a "checksums" tab to the property popup of explorer which makes checking MD5 hashes simple...
Alternatively return your card to place of purchase and ask for a refund, then buy something from the list of known working cards.
Unfortunately the SD card compatability list is a little flawed in concept if one card can work with one OS yet fail with another version as seems the case.
If a known working card can suddenly stop working when updating the RPi OS, that's an issue
And it's not at all obvious from the list if any failures have been arrtibuted to fake flash cards
Imagine if PC's ability to boot was dependant on the make and version of HDD combined with the version of OS used, and a list was used to keep track of what works and what doesn't
In reality what the RPi needs is a more reliable boot medium that is tollerant of the media itself...
[edited to clarify that copying and verifying files is not a definitive test, as noggin seemed to imply previously, best test for fakes is f3]
