Yes. From sphider's doc:
Indexing pdf and doc files
Pdf and doc files can be indexed via external binaries. Download and install pdftotext and catdoc and set there location(path) in conf.php (note that under Windows, you should not use spaces in defining the executable's path). Additionally, in admin section, check the Index pdf and Index doc boxes (alternatively, set $index_pdf and $index_doc parameters to 1 in conf.php).