I've used Archive.org for years to check previous versions of websites I've worked on and with. It uses waybackmachine.org to find and display past site versions. I just checked it this morning and NIS 2011 is claiming it's an attack site. Is this correct?
http://safeweb.norton.com/report/show?url=http:%2F%2Fwaybackmachine.org%2F
I have a hunch the issue is that waybackmachine.org has archived some sites that had previously turned out to be attack sites. But that isn't an excuse to brand waybackmachine.org as itself an attack site anymore than it would be right to brand Google.com as an attack site for having cached pages that might have malicious code in them...