I have a PHP file which is the default Landing page of my web site. Recently I have some malicious activity going on in my site and when I checked the Landing page PHP file I could see some Junk characters inside the PHP tag.
Link for the Junk characters : http://pastebin.com/JLDyZeDz
I'm not sure what is the reason I'm getting this junk characters. I cannot even decode it by Base64.
Can anyone shed lights on what has happened and how to mitigate this.