Odd behavior

Anyone noticing an increase in the amount of port 137 scans? I've seen just just over 100 in the last 1 hour. When I probe the offender I see them as MS items with their Harddrives shared wide open. Only thing in common is they all appear to have some file called put.ini in their root directory with a line that looks to be from a win.ini and states brasil.pif or exe. Maybe some new virus? Well heads up. Cheers -Joe