Reports of CDorked.A infections are still on the rise by the looks of things. The attack is reported as 'hard-to-detect', but this should only be true for the more naive sysadmins out there.
Whilst it's true that CDorked changes nothing on disk, except the HTTPD binary, this change alone should be triggering alerts. On a production server, you should be storing checksums of known good files and comparing these regularly to see if anything's changed.
As some obviously aren't following this basic step, in this post we'll look at what you need to do to at least be made aware if CDorked gets onto your system - it'd be nice to be able to do a post on avoiding it, but the attack vector is still unknown!