Regina Smola and her team at WP Security Lock are hands down the most knowledgeable professionals out there when it comes to securing WordPress and other database driven websites from malicious hackers.
I hired Regina for the first time in December 2010 and her service was so fast, thorough, professional, and above and beyond what I had expected, I have hired her several times since.
Now, I strongly urge every one of my clients to have WP Security Lock secure their website against the possibility of a malicious malware attack. It simply is not worth the risk to leave your site vulnerable to these attacks that are becoming more prevalent every day. Just installing a few security plugins is not enough to protect your website from these hackers who work day and night to find new ways to exploit vulnerable websites. Regina and her team stay on top of the latest threats and know what to do to protect their clients from them. I can't recommend WP Security Lock highly enough.