One of the things that has happened recently was that a commentator on security matters (Brian Krebs) was taken offline by a massive denial of service attack, which (not so) mysteriously happened after he published an article on denial of service attacks. The short version of the story was that his site was hit by a denial of service attack totalling approximately 650Gbps (that’s roughly 6,000 times as much network bandwidth as your typical broadband connection), when his denial of service protection threw their hands up in the air and said: “That’s too much like hard work for a pro-bono service” and gave him 2 hours to move his site.
Google helpfully provided an alternative with Project Shield, and the site was reasonable quickly available again. And to be fair to the original denial of service attack providers (which I’m not naming), this level of attack was sufficient to cause problems to their paying customers and protecting from this level of attack is very expensive.
And indeed paying for denial of service protection is very expensive; the income for the entire lifetime of this blog site would pay for approximately 2 hours of protection. If that.
There are two aspects to this attack, although to be honest neither are particularly new.
The first is technical. Most distributed denial of service attacks are quite simple in nature – you simply ask a question of a dumb “server” with the return address of the site you want to attack. If you send out enough questions to enough dumb “servers” (which can actually be simple workstations or even Internet of Things devices), then you can overwhelm most sites on the Internet.
There are two fixes for this :-
- Don’t run dumb and insecure servers.
- ISP’s should stop allowing people to forge addresses on network traffic (Ingres Filtering or BCP38).
The second fix is the simplest method, but given how successful the decades long campaign for ISPs to do ingres filtering has been, tackling both ISPs and dumb servers is worthwhile.
As this latest attack may have been chiefly by IoT devices simply sending requests to the victim, the implementation of ingres filtering may not have been of much use in this case, but it is still worthwhile – this attack is not the only one that is happening. Attacks are happening constantly. However, tackling these “dumb servers” that were controlled by the attacker is also a priority, and we need to start seeing concrete action by the ISPs to tackle their customers’ mismanaged networks (home networks in many cases) – aggressive filtering of infected customer networks, and customer notifications that include advice.
Of course ISPs are not going to like doing that just as IoT manufacturers don’t like paying more to make secure appliances. Well, it’s time to name and shame the worst offenders; the bad publicity may help to counteract the lack of incentive to invest in processes that don’t immediately help the bottom line.
The second aspect is rather more serious. We now have an Internet where it is relatively easy to silence anyone who says something you do not like – if you’re rich enough to hire a denial of service gang. Anyone that is who cannot afford protection from such gangs, and there are suspicions that some gangs also provide denial of service protection services.
And this story is not the first time it has happened, and we need to start thinking about mechanisms to keep smaller publishers online when attackers try to censor them. Unless we want all our media controlled by the big players of course.
