firewall test bugtraq news nessus nikto p2p kazaa morpheus edonkey emule free mail system pc hack internet net computer security webmaster scan check hacker wacker stop prevent network easy intrusion port analysis trojan test cable modem scanner dsl backdoor probe nmap cracker hose hosers attack defend defense worm cgi netstat netbios search update protect icmp penetrate traceroute ping protocol server open close watch ftp telnet ident pop3 sendmail vulnerability ldap dcom