Hi!

I'm not sure this is the right place to put this, but here it goes:

A few hours ago, I was stuck on programing assignment, and decided to visit the good old QuakeNet and ask for help. I joined a appropriate channel, and got a couple of good answers to my newbie question. Suddenly my computer froze solid, and it would not react to anything. X didn't react to Ctrl+Alt+Backspace, not Ctrl+Alt+Del, so I had to turn it off using the power button.

This is the first time my computer freezes like this, the log files did not reveal any HW errors. Is it possible that someone in the channel did not like my level of Java skill, and flooded me to disconnect?

By the way; Im using slackware 13.1 with the default kernel (2.6.33.4) and irssi as IRC client.

I know that if you eg. ICMP-flood someone, the traffic will be denied and, but can it provoke other behavior from the computer?

So my question is; can a IRC flood/DDoS attack cause a computer to freeze sub zero?

Cheers,
Jorek

Is a freeze like yours in the realm of possibility due to a DDoS? Yes. Is it likely? Not IMO. But it could have triggered a bug.

There is an IRC exploit that is designed to affect vulnerabilities in Cisco/Linksys firmware. I'm not aware of any exploits that affect Linux systems in the manner you described, though. I doubt it was a DDoS, but it was more than likely some type of DoS.

Without some sort of bug, it's unlikely that a system would completely freeze under a DoS. I suppose it's possible to overload a computer by making it handle all of the packets from the DoS, but to be honest, I would doubt that any reasonably modern computer could be made unusable by a DoS on any residential (I'm making an assumption there) internet connection. Even at ~25Mb/s, I doubt it would break a sweat.

A DoS doesn't have to consist of large amounts of packets. It can be one specially crafted packet that chokes up the system. It can be a 500-character URL that chokes a web server. I've seen such DoS attacks work. On modern systems even. Even residential. In fact, most DoS exploits work because of existing bugs in code...they don't even have to be 0-day.