And its a case of, they is so many virus's going around. If a goverment gets attacked with a virus that brings their whole system down then they cant just point the finger at another goverment.
They is too many reasons why people do it. Like i have a friend that captures virus's and alters them. Anyone that cross's his path that trys to bugger about with him, he sends them a virus. He also plays a game with his mates where they try and bring each others machines down. So thats 2 reasons why virus's are sent from 1 persons machine.
It is i think the case that some virus writers write a virus to catch a virus,i am not sure but in simple terms an AV programs updates are simple viruses designed to catch other viruses. Dont know if that makes sense,so that it why you should only have 1 AV program on the pc at a time in case they see each others definitions as viruses and delete them.I may be totaly wrong but it makes sence to me lol.