The ability to reproduce themselves

The core of the virus is the ability reproduce infect themselves with the file 
another. A virus has been found when the potential victims he akan 
check with them. If not then infected with the virus akan 
aksinya start with the writing of a byte in the file, 
and so copy/ write virus code objects above the target file. Some 
general way by the virus to infect / reproduce themselves is: 
a. File a ditulari akan deleted or renamed. Then created 
a file containing the virus program itself using the file name of the original. 
b. Virus program that is executed / loaded to memory akan directly infect 
files with other ways infected all the files you have.