If I missed any hacking incident for PostNuke portal. I would like to know it, drop me a message to www.blackhat.info.
PHPNuke websites mostly hacked by "hax0rs" group. Visit <a href="http://www.blackhat.info" target=_blank>www.blackhat.info and search for hax0rs ( 0 as zero).
Archive PHPNuke incident from <a href="http://defaced.alldas.org/?attacker=Tzunami" target=_blank>Alldas.Org -Defacer Tzunami year of 2001.
For PHPNuke user, upgrade your nuke to the latest release v5.5 though I'm not sure if this version address the current vulnerability of PHPNuke. PHPNuke v5.6 is coming with security update, visit www.phpnuke.org for more information.
I will complete this security analysis to give you feedback later this week.
Have a secure working environment to everyone.
TheWatcher of BlackHat.Info