What is ping pong virus???

well it could be a variety of things..from the sounds of it its probably a password virus... ping and pong...it will continuosly ping a computer till it finds a virus and pongs it..meaning it will go into a brute force mode starting with a , then ab, abc ...,etc until it matches one or your passwords saved on your computer. then it will pong it..or bounce it back to the owner of the virus...so it could be dabgerous...try Avast Antivirus..it might pick it up.