So the OpenNETCF.Desktop.Communication library has been used in the "first malware to cross-infect a handheld phone or PDA from a desktop PC binary file...." (reported by the Mobile Antivirus Research Association).

The quote from the author is as follows:

The crossover virus was written in C# (C Sharp) using Visual Studio .NET 2003, the Communications Library of openNETCF.org was used and a great help

As part of such a "first" I'm not so sure I'm proud of, it does show how pervasive something as useful as our libraries can be.