I discovered a force to eliminate the virus, without having to format the machine. Just install AVG FREE and let it perform the first scan on the infected machine. He will find by default two threats (or just one) as shown in the images, attached to the body of this text. After scanning, just clean the quarantine. However, network sharing does not come back, you have to format the machine to restore communication with NETBIOS. But the virus disappeared from infected machines for good by doing this procedure. Thank you!