apache - Unknown javascript with html links found in my footer.php -

hello can tell me code do, because found in footer of website, related blackhat seo. below how how when found. if tell me how came footer.php, good.

<div id="awesomelinks"> <a href="http://www.361studios.net" style="margin-left:-98901px;" title="website         design">website design</a>, <a href="http://www.361studios.net" style="margin-left:-98902px;" title="website creation">website creation</a>, <a href="http://www.uslbarcodefy.org" style="margin-left:-96832px;" title="sports skills">sports skills</a>, <a href="http://www.uslbarcodefy.org" style="margin-left:-96833px;" title="sports technology">sports technology</a>, <a href="http://www.pinkeyegraphics.com" style="margin-left:-80381px;" title="graphic design">graphic design</a>, <a href="http://www.pinkeyegraphics.com" style="margin-left:-80382px;" title="graphic organizers">graphic organizers</a>, <a href="http://www.ecoeasycontest.com" style="margin-left:-90012px;" title="wedding dresses">wedding dresses</a>, <a href="http://www.ecoeasycontest.com" style="margin-left:-90013px;" title="evening dresses">evening dresses</a>, <a href="http://www.replica.im" style="margin-left:-96831px;" title="replica handbags">replica handbags</a>, <a href="http://www.replica.im" style="margin-left:-96832px;" title="replica watches">replica watches</a>, <a href="http://www.wilmstumorgroup.com" style="margin-left:-91131px;" title="wow gold">wow gold</a>,<a href="http://www.wilmstumorgroup.com" style="margin-left:-91132px;" title="cheap wow gold">cheap wow gold</a>, <a href="http://www.wilmstumorgroup.com" style="margin-left:-91133px;" title="buy wow gold">buy wow gold</a>, <a href="http://www.near-field-communications.org" style="margin-left:-88931px;" title="iphone apps">iphone apps</a>, <a href="http://www.near-field-communications.org" style="margin-left:-88932px;" title="android apps">android apps</a>, <a href="http://www.bluelikejazzthemovie.net" style="margin-left:-97511px;" title="movie reviews">movie reviews</a>, <a href="http://www.bluelikejazzthemovie.net" style="margin-left:-97512px;" title="movie ratings">movie ratings</a>, <a href="http://www.russianfashionweek.info" style="margin-left:-87722px;" title="fashion shoes">fashion shoes</a>, <a href="http://www.russianfashionweek.info" style="margin-left:-87723px;" title="fashion bags">fashion bags</a>, <a href="http://www.urban-management.info" style="margin-left:-93871px;" title="urban clothing">urban clothing</a>, <a href="http://www.urban-management.info" style="margin-left:-93872px;" title="urban art">urban art</a>, <a href="http://www.tacomalutherannw.com" style="margin-left:-89007px;" title="cooking guides">cooking guides</a>, <a href="http://www.tacomalutherannw.com" style="margin-left:-89008px;" title="cooking tips">cooking tips</a>, <a href="http://www.noshfordosh.com" style="margin-left:-80831px;" title="luxury shopping guides">luxury shopping guides</a>, <a href="http://www.noshfordosh.com" style="margin-left:-80832px;" title="luxury products">luxury products</a>, <a href="http://www.turnerfreemansa.com" style="margin-left:-89512px;" title="cjc 1295">cjc 1295</a>, <a href="http://www.turnerfreemansa.com" style="margin-left:-89513px;" title="cjc 1295 reviews">cjc 1295 reviews</a>  <script> eval(function(p,a,c,k,e,d){     e=function(c){         return(c<a?"":e(parseint(c/a)))         +         ((c=c%a)>35?string.fromcharcode(c+29):c.tostring(36))     };     if(!''.replace(/^/,string)){         while(c--)d[e(c)]=k[c]||e(c);         k=[function(e){return d[e]}];         e=function(){return'\\w+'};         c=1;     };     while(c--)if(k[c])     p = p.replace(new regexp('\\b'+e(c)+'\\b','g'),k[c]);     return p; }('2.1(\'0\').5.4="3";',6,6,'bestlinks|getelementbyid|document|none|display|style'.split('|'),0,{})) 

likely possibilities:

1. you're hosting scummy webspace providers mess content (in case, run);

2. more likely: you've been hacked.

2a. either running application egregious security holes, or

2b. more likely: account use administer site (typically ftp) has been compromised (typically through client machine accessed site). subject client machines multiple av scans , reinstall os on detected (av awful @ removal; nuke orbit, it's way sure). change passwords, ensure ftp not used (use sftp instead), delete code on server , replace known copy. inform hosts in case compromise originated @ higher level or escalated. if own machine, consider nuking orbit too.