I recently bought something online from Europe, and to my surprise, inside the package, there was a brand new USB stick. Luckily, my sixth sense told me that something might be fishy. So, I always test on my old spare PC that does not stay on the network, only for offline testing. When I hooked up the USB stick, it was 2 TB and blank. Just to be safe, I tried to format it, and there was no issue. However, after a few minutes, I noticed crazy activities through the USB stick, so I knew something was fishy. I immediately destroyed that stick and restored my PC, and that's one of the reasons I tested on a PC that has nothing on it and stays offline for that purpose only. So, be careful when buying cheap or receiving free USB sticks.