Here are the 'cyber 9/11' scenarios that really worry the experts
Bricking every intel cpu,Using a likely 0 day in JunOS and ASR routers to make them all inoperable for a few days,similar wipe outs of cloud provider infrastructure come to mind.<p>But if I was the well resourced attacker I would use multiple teams and target a diverse variety of important services and infrastructure and coordinate an phased long term(weeks) attack. I would not cripple the internet as a whole,especially social media. In battle,hiding your location  and intent is crucial to victory.<p>Social media would play a critical role in sowing confusion amidst the chaos. Isolate part of the country and  spread a message that some internal political group (antifa or alt-right for example) launched a physical WMD attack,use access to fortune 500 company networks to send emails and other communication indicating internal collapse of the companies,one corp is going bankrupt,another has been lying about profits is under SEC investigation. Chaos after chaos.  The goal of a &quot;cyber 9&#x2F;11&quot; would not be to cripple the internet but (imho)rather to exploit it to acheive three independent goals:<p>1) Long term (multi?)National and Economical instability and possibly collapse.<p>2) Make the internet as it stands today a mortal threat to society.<p>3) As a precursor to a physical invasion. The kinetic attack would be only of the many rumors and reports being circulated. Any and all damage to your enemy&#x27;s communications  brings you one step closer to victory with minimal effort.<p>More on goal #2: The goal of 9&#x2F;11 was not to kill some americans. The goal was to destabilize the west by attacking important symbols of economic and political prosperity. It worked,economy was only momentarily destabilized but 17 years later america and the west are grappling to keep their democracies and basic freedoms. The goal of terrorism is to terrorize not to merely kill(which is why mass shooters are not labeled terrorists,their intent is murder not change through terror). A Cyber 9&#x2F;11 would have similar goals where the intent is to change and cause long term weakening of the adversary.<p>What makes the internet strong is not BGP,DNS and secure operating systems. It&#x27;s the fact that people trust it for reliable and resilient communication and governments view it as a strength to their  political and economical stability as opposed to a dangerous liability. The goal of terrorism is to change your beliefs so that fear resulting  from the attack changes your policy and principles.