Any method that tricks remote computers into minor computation without their knowledge using algorithms present in the communication software.
Originally coined by physicists Albert-Laszo Barabasi and Hawoong Jeong and computer scientists Jay B. Brockman and Vincent W. Freeh of the University of Notre Dame in Indiana using a scheme that co-opts error detection in TCPIP communication algorithms.
Remote exploit tools like the DDoS tool Tribal Flood Network (http://www.cert.org/incident_notes/IN-99-07.html#tfn) are not ParasiticComputing. GridComputing and remote exploit tools require installing special software on the host. ParasiticComputing does not.
Interesting concept. First I've heard of it. Can you provide an example or snippet?
http://www.nd.edu/~parasite/ has some good info
See: ParasiticCompiler