The plugs arrived today, a little over 2 weeks since they were ordered. I googled "fake NGK spark plugs" and found a bunch of sites that showed how to distinguish the fakes from the real deal. Google even offered to help me buy fake spark plugs, in case mine turned out to be real!
By all indications, these are real.
The box has "spark plugs" written in Russian, something that is missing from the known bad ones.
I compared the plugs with a new one at Autozone. They have all the right markings in the right places, and the gasket is identical to the real ones. These are two areas they say are different on the fakes.
I think they're OK, but it's worth my peace of mind to buy some over the counter from a store I know and trust.