Several years ago (in 2005), researchers at MIT released a paper-generated machine, SCIgen, that can produce fake computer science papers. Since then, more than 120 such papers have been found to have been accepted and published in conferences. Recently there was a report on Scientific American / Nature on the phenomenon.
There is another interesting observation in the report, “Most of the conferences took place in China, and most of the fake papers have authors with Chinese affiliations.” The report did not explain further why that was the case. However, a number of possible and obvious reasons come to mind quickly.