Subtitled "The First PC to Windows Handheld Cross-infector", this multi-page article covers much more ground than the title implies.
The author is a principal of MARA (Mobile Anti-virus Research Assn.), which has come under some criticism recently for not sharing some bits of malicious code with other researchers unless they joined MARA. Membership in MARA is free, though it is my understanding that the agreement you must sign to join places burdensome restrictions on some researchers.
Aside from that, the article tells some of the "nuts and bolts" details of recent mobile infectious code. It's worth the read, and enduring the author's defensive tone regarding MARA. If you read it closely, as I did, you will in all liklihood find it scary. These threats are the coming thing and will require quite a bit of vigilance and some crafty software tools to keep us safe. Do not be led to complacency by the relative crudeness of the code in this example. This type of malware is growing in both sophistication and in numbers of attacks, very rapidly.