I know from first experience on some of the production facility in china for ICs. For e.g. if a semicon fab is making an IC , say for Microchip 93LC46B. If they figure out that the parts are selling in large volumes, they would start an alternate production unit for this. Those units would NOT be delivered to microchip, but to the local market for assembly. When they leave the semicon fab, these ICs would be un-marked, in order to protect IP issues and other legal clauses. Once in the local market, these would be screen printed or laser etched with the part number and Microchip logo. It then ends up in the assembly units when these parts are requested by some one who is assembling a board. Now in this case Microchip does not make any money as the product never comes from Microchip. But the end user does not know it because the parts look and function the same as original.
The only problem is when someone in the local market makes a mistake and prints the wrong part number on the blank ICs which came out of the fab. That's what you have got now.