I searched the web and apparently this process has something to do with the iCloud Drive! I don't have more than 10 MB for all the data and documents on iCloud Drive; but this process uses more than 300 MBs everytime it starts. It usually starts within a restart of the computer. I also checked the setting of iCloud drive on my iPhone and disabled all data backups and stuff for applications (even whatsapp and others which are not even on my mac). I have no idea what's causing this bandwidth hug. All photos cloud stuff has been turned off too. I don't use safari either; using chrome.
So what exactly is going on? Is the only way to fix this, turning off the whole iCloud Drive thing? Is this a bug? I'm using Yosemite 10.10
I like using iCloud drive to sync all Pages and Numbers documents between my iPhone and Mac (Which together are not more than 10 MBs).