Is it possible?
What's a CMS detector?
I frankly don't know.
Why would you want to hide this?
Just don't want others to see which cms I'm using.
Security through obscurity is not security at all. While you can take steps to make it less likely that they'd identify it, there's no guarantee you could do a perfect job. The most recognizable attributes of October are the default cookie name (October_session), the default backend url, and the Ajax framework which loads from the system module and has recognizable headers and data attributes.
Maybe rename the /backend URL ?
No, that's not enough.
There are MANY ways one can verify which platform is used to build a website... for example, checking if the URL
/wp-content/ returns an HTTP 200 code would tell you if it's running Wordpress...
1-8 of 8