This computer virus works like this:
First, during its incubation stage, it gains control of a large number (a million or so) of victims' computers and bank accounts (or paypal accounts or similar).
Then it arranges its victims in a hierarchial tree. Say each victim is connected to 10 victims
one step down.
Now the active phase of the virus begins. Starting with the lowest victims (the majority), it transfers $1 from their accounts to the accounts of the victims one level higher.
These will recieve $10 each, from which half ($5) is immediately transferred to the next level up. Each of these will recieve $50, from which $25 is passed on, etc.
The process is repeated until a large sum of money ends up in the top level victim's account. Finally, half of that is transferred to the virus creator's account.
The beauty of this scam is that nobody is likely to complain much. The majority of victims who lose $1 won't think it's worth the hassle and paperwork of filing a fraud investigation. The few ones who *do* bother going after their dollar, will only get as far as the next layer of victims. Some of those might have to give back a dollar or two, but even then they'll still have benefited from the scam, so they are even less likely to take action.
They further up the pyramid the investigation travels, the less cooperative/ more apathetic the victims are going to become.
By the time the scam can finally be traced back to the highest level victim (if it even ever gets that far), so much time will have passed that the virus author will be impossible to find.