Take care guys, my site was hacked 2 days ago.
You have already the Viagra people here. They enter through your PC via Trojan virus.
Scan your PC for a file with name "msauc.exe" it's the backdoor of the virus.
They try to modify all the index.php on your server, so have backup's.
Very good tool to detect and remove : www.spynomore.com/