Tell-tale Signs that a Site has been Compromised

If a website is compromised by a careful, talented, and well-funded attacker, then the scary reality is that no one will probably ever know that the site had been hacked at all. However, most attackers are not well-funded, not in the sense that we’re talking about, they’re using pre-made, for-profit exploit packs designed so that anyone, regardless of talent, can use them, and, like anyone else, they make mistakes.

read more........http://blog.kaspersky.com/signs-of-compromised-site/