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Comment on Understanding the recent DDoS attack against Read the Docsparent

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most attacks were 90 seconds long ... there's no way I'm convincing an ISP to drop a pwned customer over that.

Every victim (such as readthedocs), or even people sharing blocklists to avoid becoming a victim, blocking that ISP's ranges until they do clean up their network could be a convincing argument?

As you say, even at 90 seconds, it's clear to all involved parties that the customer is pwned or malicious. Such a reoccurring source of abuse needs to either clean up or find themselves a different ISP to spread harm onto the net

I get what you're saying about that this won't solve an ongoing attack right this minute, or even by next week. But if we just let it all happen then the solution is going to be either (1) we all buy equipment that can handle something like a terabit per second and arm our infrastructure to the teeth or (2) centralize all traffic through a vetting entity who decides which client gets to visit the internet today. So far we're headed towards the latter and nobody really wants that. Abuse messages will have to slowly trickle down from victims to originating ISPs to users, and if users didn't willingly sign up, then to wherever users are getting this malware (Google's app store will be a big component). Stopping this at the source seems to me a much more desirable long-term solution

www.uceprotect.net does that for email. It's a DNS blacklist that puts hole networks on it, even if "only" a individual hosts SPAMs.

It's a double-edged sword. That is how you end up with most ISPs blocking port 25 completely. If your hosting provider is on the list you are collateral damage. You yourself can do very little to remedy the situation except to beg your provider "to look into it".

What do you expect the ISPs to do in this story? We are talking about TSL connections. Block port 80 and 443 and expect the costumers to use your HTTPS-Proxy. Than they could inspect and block individual actions.

As you say, even at 90 seconds, it's clear to all involved parties that the customer is pwned or malicious.

It sure is --- but an ISP would want to observe the traffic themselves, and if it's a 90 second attack every so often, chances are they won't see it when they look. When it's volumetric reflection, you can probably tell them how to send a request and see the response, and maybe they'll contact the customer, but maybe they'll just sit on it. As a victim, the ROI for reporting just wasn't there.

I wasn't getting huge traffic flows, and I was mostly getting attacks against www, which wasn't my actual service, so making sure volumetric attacks below my interface rate were shrugged off and taking simple actions like dropping requests from http clients with user-agent Wordpress were good enough. If the volumetric attacks were much over 10G, my host would have null routed my servers, which is annoying but highly scalable --- many ISPs support a BGP blackhole community, so my host can add my attacked IP to that and their upstreams will drop inbound packets when they enter the ISPs network.

I can't find a reference now, but I've seen things that allowed for more specific blackholing, such as by source or destination port number or by protocol. If my host's ISPs are dropping all UDP and IP fragments to my IP under attack, I could keep serving my TCP traffic and ignore a huge DDoS. I wouldn't even be able to measure the size of the DDoS.

Every victim (such as readthedocs), or even people sharing blocklists

The report makes it pretty clear that the attack was distributed enough that profiling for blocklists was ineffective.

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