grep 'default.ida' /path/to/access_log | awk {'print $1'} | sort -n | uniq | this_perl_script.pl

##</code><code>##

#!/usr/bin/perl -w

use strict;
use LWP::Simple;

my $ipaddress;

# Message to the sysadmin who is infected. I've kept out unusual 
# punctuation on purpose
my $message = <<END;
You are infected with the Code Red II worm and it is bloody annoying. For details head to http://www.cert.org/advisories/CA-2001-19.html
END
$message =~ s/ /_/g;

foreach $ipaddress (@ARGV) {
        my $full_url = "http:\/\/$ipaddress\/$message";
        my $junk = get($full_url);
        }