It's really anything branded as by "Apple" on Amazon.
Look at the reviews of the Apple Thunderbolt Cable [1] -- 40% are 1 star reviews and many mention the cable being fake.
Similar story on the Apple USB Ethernet adapter [2]. I bought one a few years back and it identified itself with Chinese lettering in System Preferences.
Ken Shirriff did an amazing teardown of fake Apple chargers [3] and found a number of safety hazards relating to high voltage isolation. Teardown of the USB Adapter [4] found it used a part that doesn't exist (label does not match any known package for that IC).