title: tools to find inject malicious code?
body: <p>I search a tool to find inject malicious code in my PHP files.
  In each PHP file I had this inject:</p>
  
  <pre><code>eval(gzinflate(base64_decode('pRlrc9u48bM70/+AaBhTjGmJol5WbNpJE+fuZppLqjid6di...
  </code></pre>
  
  <p>Of course I use the shell to find and replace the inject. But each hour the inject is back. So some PHP file(s) are injected. I've more than 34 websites on this server - each website are injected.</p>
  
  <p>My question now:
  Has somebody an idea to find the security hole?
  Maybe a online tool or a script which I can check all PHP files?</p>
  
  <p>Thanks for your help.</p>