Retail FX8350 Came with gray-fingerprint

[theAspiringPCGamer]

I just bought a new computer build off of Newegg and my Fx-8350 has this gray fingerprint looking thing on the top left of the CPU. The package was sealed, however the corners and edges were a tiny bit worn, etc. (I understand it's an old processor) So what does this mean? Is this just left from the testing of it or have I been ripped off? Since I have opened the box, is it too late for a refund if it works? Any input helps. Thanks guys 😀

 

[ronintexas]

That is thermal paste. You need it to properly transfer heat from the CPU to the cooler.