Yep, I was about to post that we just hit #3.  
This little battle:
iamwiz82	124
thecrecarc	130
drpizza	131
tuxdave	133
wahoyaho	141
huh2142	142
bucwylde23	143
has been going back and forth.     The rest of you losers need to upgrade to virus level 8, STAT!  (So ATOT can take 2nd place)
It pays off fast.   There are plenty of high ranked people who have quit? the game and can be attacked easily, with as little as 20 or 30 thousand kbps.  (or less even)
The level 8 virus pays off pretty quickly & then some.   So, while it might cost 1,920,000 up front,  in no time, you'll be up to 20k infections or more.   That translates to 100k credits per tick.  At that rate, half a day has paid off your virus.  Then, it pays for itself again in 1/4 day, then in a couple hours...    
Sticking with level 6 virus is like driving an old clunker with poor acceleration.   Sure, eventually you'll get there.   But, sometimes it's better to pull over, get into the super-charged car that accelerates much better, and get in the other lane.