Computer viruses and other legal procedures, is an executable program, but it is not a complete program, but parasitic in other executable program, so it enjoys all the program can get power.

Since the effect of parasitic elements limits the output voltage and power transfer efficiency of DC-DC converters, voltage lift technique opens a good way to improve circuit characteristics.

Conducting Electromagnetic Interference (EMI) in switching power supplies caused by parasitic parameters and transient characteristic of power electronic elements is studied in this paper.