Has anyone else had any experience with a perl/php hack that places a file called f.txt, alltheweb.txt, yahoo.txt and similar files? f.txt is XxX-SuperScan-XxX, and the search engine text files are lists of sites.

We're just piecing together how they got in and what's been affected - if anyone has been similarly hacked, I'd appreciate whatever advice you can give me. (Yes, I searched before posting this. )