Finally, I have found an answer to my previous question. The security scanner that leave this signature is DFind.
Doh! like Homer Simpson 🙂 The word DFind is into the signature itself!
Anyway searching on Google I can find these URL:
DFind is one of the smallest security scanner tool and knowing the URL, you can download and check if your server can be compromised.
Ho scoperto finalmente che è DFind il programma che lascia questa strana stringa nei web server log.L’utility si trova qui:
P.S.: Thanks to Koon Yaw Tan