Now to identify a fake USB, check the two holes again, if its silver colour, it means its aluminium, which is fake. Although aluminum has only about 60 percent of the conductivity of copper, but the tensile strength is very low( which tears apart when subjected to stress) Which makes your USB to to fluctuate. If you are using this type of USB, you will be experiencing partial contact. Most universal modems in Nigeria market today are made with this aluminium contact, because aluminium is cheaper than copper, and the manufacturers/ importers make more money from such.
The photo below clearly shows the two holes that reveals the bus/contact. The bus used for the USB is made with copper, that is why its golden in color