Firstly, apologies if the category for this question isn't perfect but I thought this was the best fit...
My host counts traffic usage as that from sites and from what it calls "local" traffic. Recently I have noticed that "local" traffic has become huge: some days it has been over 25GB (about 20x that of all my site traffic!). It's always 6GB+ now. This is the "In" traffic. "Out" traffic is only about 4mb (which is about what it has always been - the "In" traffic also used to be about this much).
I have contacted the host who has assured me that it is not a problem with their statistics. However, they can't give me any more information as to where all this "local" usage is coming from. All I have found out from them is that: "the local traffic is generated between MySQL ,FTP and Apache servers".
The only FTP account is mine which I might use to upload a few mbs of files each day. The SQL db is ~0.1mb, queried about 500 times a day. The only complicated thing the server does is a Paypal IPN, executed about 4 or so times a day. There has been no major changes to any of the sites lately.
My question is: how do I find out where all this "local" usage is coming from?
Is there any chance this is down to a security problem? (Just to be sure, all the passwords were changed but the problem still persists...)
Thanks in advance for any help,