Security – PHP files flooding wp-content/cache/

HI All,

I just wanted to see if anybody else has come across this one.

I was alerted yesterday by my host that I was getting 100’s of inbound requests which they are quarantining until we can suss it out.

In the root /wp-content/cache.. I am finding 100’s of php files which begin with about 30 numbers ad letters IE 3745vhyd857273gbidt78.php. They are always writing to the a folder which beings with 3 random letters. Sometime they are in the Object and sometimes in the Db cache etc.

I am using WC3 and cloud flare. Obviously there is caching going on – and of course I would expect to see files here. But it was the level of the requests we are getting and the file structure.

As I do not quite understand the mechanics of WC3 I was hoping that somebody might explain what I should be seeing in the wp-content/cache.

I can eliminate any that look weird.

Thanks all.