I think you are referring to the following recent news:
“Now research assessed by the US Centers for Disease Control has revealed that surfaces in cabins occupied by infected passengers continued to harbour the RNA (ribonucleic acid) of the virus responsible “for up to 17 days after cabins were vacated on the Diamond Princess”.
RNA is material that carries genetic information. It can indicate if the virus was present but does not indicate the virus was still alive. “
I wouldn’t worry about that, the studies on actual viable virus that could infect a human have shown that 24 hours on cardboard and 72 hours on metal or plastic to be appropriate rules of thumb to manage your external packages by. Within those periods, the risk decreases rapidly at the beginning (like a Half-life decay)