Last week I was part of a team to analyze how a common exploid start its work. The first thing I noticed: it reads either the README.txt, REALEASE_NOTES.txt or UPGRADE.txt
Well, this can be used to discover the exact version information of your openx installation. With this knowledge the person (or script) at the other end knows within seconds which bugs are already fixed, and which he can use.
So it is allways a good advice to rename or delete those files.