Obviously, the CC virus is originally from Russia. It is a simple resident parasitic COM infector. Its length is only 145 bytes, and that is unbelievably little when compared to what it is able to do: the virus can detect appropriate victims as well as itself; it manages double installation, copies its code to the area of the table of interrupts vectors (to its upper part), redirects the interrupt for DOS services and performs the infection. The infection itself is done by copying 145 bytes from the beginning of the file to its end and locating the virus body to the freed position. This, less traditional technique of infection causes that some anti-virus programs – working on the principle of integrity check – may have problems with the virus removal. The CC virus slightly alters the DOS service 4B (EXEC) and introduces its own sub-function CC (that is where the virus name comes from).