It is very common on new drain installations. It is hard to get a good feel for how tight to tightnen the backing nut, and then the putty oozes out. All that needs to be done is to snug up the nut underneath the sink and wipe up the putty with a paper towel. I can assure you that it was pretty and perfect when it left the factory, a little time, some hot water, and then the drain sets better in the sink. I have seen it many times, and it happend with our new house, and our new travel trailer.
2015 Starcraft Travel Star 299BHU Black Pearl Edition
2011 Jayco X23J (traded in)
2009 Ford F150 FX4 SuperCrew