Take a look at the perl scripts (for example go.pl)

The images .gif are in reality php scripts (food.gif and food2.gif)

The scripts modify also the crontab and add:

#* * * * * /home/pi/udevd > /dev/null 2>&1 & #* * * * * /tmp/romerito > /dev/null 2>&1 & #* * * * * /home/pi/kblockd > /dev/null 2>&1 & #* * * * * /var/tmp/tfti > /dev/null 2>&1 &

I was running raspbmc on the raspberry pi.

It seems the scripts were there before and got activated just today.