Clean up Wordpress Virus

find.php

<?php
        function run_dir($dir)
        {
                $d = opendir($dir);
                while(($f = readdir($d)) !== false)
                {
                        if($f == "." || $f == "..") continue;
                        if(filetype($dir . "/" . $f) == "dir")
                        {
                                run_dir($dir . "/" . $f);
                        }
                        else
                        {
                                $a = explode(".",$f);
                                if($a[count($a)-1] == "php")
                                {
                                        // do pregex here
                                        $contents = file_get_contents($dir . "/" . $f);
                                        if(preg_match("#eval\(base64_decode\(\"[^\"]*\"\)\);#",$contents))
                                        {
                                                myecho("Infected PHP file: ".$f."\n");
                                                $newcontents = preg_replace("#eval\(base64_decode\(\"[^\"]*\"\)\);#"," ",$contents);
                                                $a = file_put_contents($dir . "/" . $f . ".infected-bak",$contents);
                                                $b = true;
                                                if($a) $b = file_put_contents($dir . "/" . $f, $newcontents);

                                                if(!$a) myecho("\tFailed to Backup\n");
                                                if(!$b) myecho("\tFailed to Clean\n");
                                                if($a && $b) myecho("\tBacked Up & Cleaned\n");
                                        }
                                }
                        }
                }
                closedir($d);
        }

        run_dir(".");

        function myecho($words)
        {
                echo $words;
                file_put_contents("cleanup.log",$words,FILE_APPEND);
        }