title: What is the meaning of ${$"\x47L"... this syntax in PHP?
body: <p>I found some malicious code inside my php pages, and I understand that the obfuscation is being used, but I never saw syntax like that in PHP.</p>
  
  <p>example 1)</p>
  
  <pre><code>${"\x47LOB\x41\x4c\x53"}["\x76\x72vw\x65y\x70\x7an\x69\x70\x75"]="a";
  </code></pre>
  
  <p>example 2)</p>
  
  <pre><code>${${"\x47\x4c\x4f\x42\x41LS"}["\x64\x77\x65\x6dbj\x63"]}="\x23d\x665";
  </code></pre>
  
  <p>So the question is what is the meaning of that code, and how does the PHP process it. I'm mostly curious about "${" in the begining of the line.</p>
  
  <p>Thanks.</p>