http://www.f-secure.com/v-descs/skulls_d.shtml

Skulls.D drops SymbOS/Cabir.M worm into the phone, disables system applications and third party applications needed to disinfect it and displays animation that shows flashing skull picture.

Information on the original skulls:
http://news.com.com/Skulls+program+kills+cell+phone+apps/2100-7349_3-5460194.html?tag=cd.top