They call me the content machine. I write about information security topics, with an emphasis on cryptography and distributed denial-of-service (DDoS) attacks. I've written for DarkReading, SC Magazine, and Network World. But most people know me from my monthly column at SecurityWeek.
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Here's an opinion piece about the giant new Thingbot lurking in the Internet Of Things.
Here's an interview that Oscar Visaya and I did for Raymond Gregory of Malaya Business Insight in Manila. Raymond got everything right.
I've been a cryptocurrency skeptic for years. Much of that skepticism comes from hundreds of hours of talking with real CISOs and directors of security about how they can better protect real (not virtual) currency. Even with the resources of enormous budgets and huge security teams they can barely keep the hackers from stealing all the monies. When F5 Labs asked me to write up my opinions about Bitcoin, I threw this together. Not a bad little piece.
Maria Korolov interviewed and quoted me extensively for a Data Center Knowledge piece on WannaCry. I had no time to prepare for this interview, and was surprised when it got published. Sometimes I prepare a LOT and nothing comes of it. You never know, I guess. Just keep doing them.
My writeup of the 25th annual DEF CON, the world's premiere hacker conference in Las Vegas, Nevada. I've been going since DEF CON 7. What has changed? You'd be surprised at what has, and what hasn't.
Three researchers, two from Bastille Networks, gave a fantastic talk about reverse engineering the Comcast and Time Warner home networks. Really well done! I was surprised no one was writing about it, so here you go!
Can you believe The Blackhat Briefings (now just Blackhat USA) have been going on for 20 years now? I've submitted talks a few times, but have always been turned down. I'm still hopeful for the future though. Here are my impressions of Blackhat 20.
In Singapore I did a media event espousing F5's original IoT research. Here's a write-up from Networks Asia (or Security Asia) not such which.
Cool - DarkReading published a condensed version of my Profile of a Hacker piece. There's a huge backstory behind this that I can't really talk about publicly, but buy me a beer sometime and I'll tell you.
The explosive second half of the profile of famed hacker Sabu.
Sabu was such a rock star in his time. His character and his exploits were legendary at the time and his downfall even more so. I really enjoyed writing this one. I actually had more information on this but couldn't publish it to due privacy concerns. But buy me a beer sometime and ask me about it.
Hacked the waitress at my local breakfast joint. Actually not really, but I could have. Here's a five minute write-up of how easy it can be to hack into Wi-Fi hotspot.
A young hacker came up to me after a talk in Belgium and told me this story. Made for a great article for SecurityWeek.
Wrote this cool script to kill Mirai bots that are attacking your website. Use at your discretion!
Here is an early reaction to the Dyn DNS DDoS attack of Friday, Oct 21. I spent about 8 hours working on an article about the Brian Krebs attack from an airplane over the Atlantic. About halfway through, the Dyn attack happened, and I had to rewrite the article! It was a long day, but at least when I got down there was a decent article ready to go :)
The right guy at the right time. Here's my take on the huge DDoS attacks of September and October 2016. Had to rush this one to release as an official company position on the attacks. I like how it came out.
User federation is absolutely the best way to provide user authentication in the cloud. But the recent Yahoo! breach may have dimmed enthusiasm for federated Yahoo! logins, which is a shame because reasons. The reasons in this piece :)
Q: Explain who you are and what you do
Thank you. Before we start, I need you to promise me something. You can only ask me one question about Donald Trump, okay? No more than that.
Q: How long have you been at F5?
I’ve been at F5 for 16 years, which is an eternity in the tech world. I was the last person hired during the so-called dot-com bust, during which time a hiring freeze was put in place. On my first day, there were already rumors of layoffs, and I thought “oh no, I am the new guy, of course they will eliminate my position!” So I worked day and night to show my value but I six months later I was still “the new guy”. One day the police sent us a picture of a dead body in an F5 T-shirt and I thought “oh no, the reduction in workforce is really starting!” But it turned out to be a homeless man who had gotten the shirt from the local food bank. Anyway…
Q: Many people know F5 from their ADC solutions, why the increased focus on security these days?
Yes, many people know F5 as the world’s most-expensive, I mean the world’s best load balancer, but what they don’t realize is that we’ve spent the last 10 years moving into Security. There are two reasons for this.
First, the reason it is called an ADC and not just a LB is because it naturally consolidates adjacent functions, such as caching or acceleration but now security functions like firewalls as these technologies become commodities.
Second, F5 is the number one commercial SSL termination device. If someone is paying to decrypt SSL, they are most likely deploying F5 devices. As more and more of the world’s traffic goes encrypted, it makes the F5 the first device in the network that can do layer 7 security controls. And that means attaching WAF functionality, or doing cookie inspection, or passing through to devices like FireEye. Q: You travel the globe as part of your job – do you see that security has a different place on the agenda here in Europe than North America for instance?
This is my 13th country, and fourth continent visited in 2016. So I do get to see a bit of how businesses are dealing with security around the world. What I can say about Europe is that continually impressed at the technical depth of the security professionals here. In my opinion, Europe has the best defensive security expertise in the world. There are so many excellent security conferences here, such as the CCC in Germany, RSA Europe and Hack-in-the-box in Amsterdam. The level of security awareness among everyday operations people is excellent as well.
Belgium functions as a hub in Europe. Many organisations have European headquarters here and you have institutions like the European Parliament and NATO. Naturally the security demands of these organisations are extremely high. Perhaps this is also one of the reasons the security expertise in EMEA is so high and organisations like Securelink are instrumental in maintaining the security at the highest level.
I remember one conversation I had with a customer in eastern Europe, and then first thing he said was <accent here> “David, ve will not put our data in Amerikan cloudt.”
Q: What about Australia or New Zealand?
Australia is the opposite. They are SUPER friendly with public cloud. In 2012 one of the CIOs of their four banks gave a keynote where he announced that his bank was aggressively adopting a “cloud first” strategy. Now there are telcos there that are trying to re-sell “multi-cloud” solutions but it’s tricky. Multi-cloud might seem like the ultimate availability solution, but I think we’re years away from consistent, reliable APIs.
Q: What about Africa?
Africa has its own challenges. In Nigeria, distributed denial of service is getting to be a thing, so of course we try to sell them our DDoS service. This service is classified as “Insurance” but nobody in Nigeria believes in insurance and even if they did, they want the premium to be approximately 0 euros.
Also, a big security thing in Africa right now are little plastic physical locks that you put on your Ethernet ports. They are locked with a key. [ aside: they keep the key taped under the desk ]. That’s Africa.
Q. We see many organisations looking at their cloud strategy, public vs private etc. How do you think organisations should handle their security when moving to a hybrid or public cloud scenario?
Let me give you three short cuts for cloud security, whether that’s public, private or hybrid.
For users, deploy federated logins using SAML assertions. You get SSO and don’t have keep your passwords in the cloud. And if you do it right, you can even prevent your passwords from ever transiting to the cloud and back. There’s a trick to it and we’re helping a lot of people right now who are transition to Office 365 and don’t want the CXO passwords going to Microsoft.
Second, for applications, when possible, embed your application security policy into your applications! So if you move them to the cloud, the policy goes with them. Or if they burst here and there or jump clouds, the policy goes with them too.
Lastly, if you’re considering moving to the cloud, leave your really old legacy stuff behind. If an app isn’t based on a recent Windows or Linux suite, it’s often not worth moving it to the cloud. The analyst firm Securois has an interesting term for people who try to move their really old apps to the cloud: cloud tourists. They visit the cloud, look around, start to spend some money, realize that it’s a sunk cost and not going to get them any value, and they go back home.
Q. Let’s talk about so-called Hacktivism. You track Anonymous, right? What is Anonymous doing?
I love anonymous. They used to have a brilliant leader named Sabu (expand). But lately they’ve been somewhat floundering – not a real central figure since then ( e.g. Anonymous 127.0.0.1 story).
However, they have launched their own political party in the United States called The Humanity Party, or ThuMP for short. It has three main tenants, the first of which is to establish a single, united one-world Government (the United Kingdom has already voted out of it). The other two are social equality and um, free WiFi for everyone. Can’t say I disagree with that last one. Instead of donations they invite you to Like their Facebook page.
Q. Let’s talk a moment about cryptography and SSL. What is new there?
Ivan Ristic, the author of the book “Bulletproof SSL/TLS”, runs an SSL scoring service over at Qualys SSL Labs. The scoring uses the grading system, A, B, C, D, F, which is nice because I can remember that.
So for the last five years, half the SSL administrator’s I’ve worked with are trying to get an A+ on their website. And it’s not just pride because people are writing articles basically “SSL shaming” entire industries. It started in Australia where Troy Hunt (the owner of the HaveIBeenPwnd website) posted the scores of all the banks in Australia.
But I’ve seen that done in Poland and even here Belgium as well. In the states, someone posted the SSL scores for all of the presidential candidates. Wouldn’t it be cool if that’s how we actually choose our presidential leaders? By their cryptographic security posture? That would be much better than how we’re doing it now, because apparently whatever we are doing isn’t working very well.
Would you like to know what Hillary Clinton gets?
She gets an A, but it’s actually a private server in her laundry room.
Q. What do you see as the most serious security threat?
There are rumors of the Russian’s hacking our election and trying to throw it to Donald Trump. Why they would do this, other than as the ultimate party joke, is sort of beyond me. But it is quite concerning. Security professionals have been warning about the dangers of automated voting systems for years, and I worry that people aren’t taking it as seriously as they should. I would imagine that you’ve been doing it here for years, and it’s working?
But if you meant “what are the most serious threats to the Enterprise” I’d have to say Malware. It has been the number one threat this year, and the last five years running. That’s why FireEye was such a security darling. The biggest problem with malware, at least in the states, is that all the malware authors know that they need to hide their malware inside SSL connections so it won’t be detected.
In the States we can decrypt that traffic (if the customer wants) and clone it over to FireEye or an IDS. You can’t do that in many places here in Europe, and I’m interested to see how that works out. Q. To what extent is IoT the next driver for increased security risks?
Do you know what an oxymoron is? Two words that don’t go together, like ‘military intelligence’ or ‘found missing’ or ‘Microsoft Works’. Well ‘IoT Security’ is like that. It used to be a joke until about 2 weeks ago, when someone launched a 620 Gbps attack using (at least partly) a new IoT botnet. That was the largest DDoS attack I’m aware of, though the record has possibly been broken since then.
Most IoT devices connect one-way up to a cloud module, so that’s good. I think IoT security is going to be a huge issue for a long, long time because that’s basically a brand new industry. I mean, the Internet has been around for 30 years and it’s still far from secure even with every researcher in the world trying to fix it, so why would anyone assume the IoT universe won’t be anything but suboptimal?
I think for Europe this is a real challenge and opportunity. Germany is still the economic powerhouse of Europe, and they rely on manufacturing. They absolutely have to get IoT security right as they build their internet-connected cars and airplane engines.
Q. How can do you provide protection against multi-faceted DDoS attacks?
I just wrote a whitepaper called the 2016 DDoS Trend analysis, and buried within that paper are 8 references to Huey Lewis. I mention that because no one has been able to locate them all yet and I have gift card I need to give away.
But in our paper we note that we now see the majority of DDoS attacks as comprising multiple attack vectors and they’re getting more sophisticated, too. For example, stateful TCP floods are way up, and on some days they are outnumbering stupid UDP floods.
So we have some customers who don’t want to deal with any of it at all and just contract us to handle all their attacks for them 24/7. But many other customers are going for a blend of cloud-protection and on-premises DDoS.
For on-premises, if you have an F5, there’s a LOT you can do. We have a best practices document that shows you how to handle every DDoS attack type we’ve ever seen. Just google ‘David Holmes DDoS Recommended Practices’ and you’ll find it.
Q. Looking in a crystal ball, where do you think the security threats will come from in 5 to 10 years?
First, let me say that I think people are terrible at predicting the future. Just awful. With that said, let me um, try to predict the future.
I think finding sufficient entropy will continue to be a source of frustration among security professionals. Computers today are awful at getting real random data from which to generate keys or other cryptographic material, so everyone cheats at this. Professor Nadia Heninger from the University of Michigan has done some amazing work here [talk a little about her work]
Time synchronization is going to be another sore point. Real authentication and authorization systems require at least some kind of crude but secure time synchronization. The Internet has always been terrible about this so both Microsoft and Google are coming up with their own secure time mechanisms.
Lastly, as I get older, I am really hopeful that we will achieve The Singularity before I expire.
I've been coming to this hacker con since Defcon 7. So that's 17 years! DC24 was a good one, with some interesting talks. Here's a recap I did for SecurityWeek.
Here's a recap I did for SecurityWeek of some of the more interesting talks at the 2016 Black Hat security conference.
F5 commissioned the analyst firm IDC to survey hundreds of infosec professionals. The goal was to find out exactly how much enterprise traffic is encrypted. Their answers? Between 25-50% in 2016. That's a lot! Read the survey to find out how infosec is dealing with all the encrypted traffic, and the malware that hides within.
I get lucky sometimes. This was one of those times. I ran into a member of CERT.be, and he told me of an interesting report about a cyberespinage case in Europe. Made for a great SecurityWeek article.
After I came back from my 50 days in Asia, I wrote up three observations about how infosec is different there. Some good analogies. Kinda proud of this piece.
When asked for Comment on the Panama papers, I said heck yeah, there are so many questions. So I put them into a SecurityWeek byline, and then answered them. Most of them. Even the one about Simon Cowell.
A look at how a Dridex malware campaign is shifting around the globe.
Not every day you get on the front page of the local paper! Was in the Philippines immediately after the first SWIFT banking theft: $81M had been stolen (by the Lazarus group, probably) and laundered through local casinos. I happened to be there speaking with the media about bank fraud anyway, so that's how country manager Oscar Visaya and I ended up on the front page of the paper.
The idea for this, my favorite article, had been rattling around my head for years. "Why don't you use your knowledge for evil?" I surveyed over three dozen of my friends and colleagues to find out what their prices were, if any. Some illuminating results.
F5 Network security evangelist David Holmes offers concrete advice about how cloud outsourcing can help companies with a talent shortfall solve three enterprise security problems: application security, penetration testing, and bug bounties.
A look back at the mega breaches of 2015: Ashley Madison, the OPM hack, Kaspersky, and more.
A BGP route monitoring firm, Qrator, released a paper at Blackhat 2015 titled “Breaking HTTPS with BGP Hijacking.” Here's my take on it.
I first ran into the hacker search Shodan engine at Defcon over a decade ago. It's still around; I saw its creator, John Matherly, giving a talk about it in Amsterdam's Hack-in-the-Box conference. My summary for SecurityWeek.
A deeper dive in to the theoretical topic of mobile malware.
A launch blog for the SilverLine DDoS Protection service.
Three different reasons why tractor companies find themselves in the crosshairs of DDoS attackers.
I've been scanning the SSL universe since the summer of 2014, so I was able to see the effects of the POODLE vulnerability. Here's the writeup I did on both for SecurityWeek.
The reputation of IP addresses is can be used to create intelligent security controls. Here's a white paper for how to leverage that control.
This is almost top secret stuff. I probably shouldn't even be writing about it, but other's have, so if someone were to weaponize this, well I can't be held responsible. And at least I provided a defense.
As you would imagine, being a security and networking professional, I ran a pretty sophisticated home network. One time I plugged our partner Webroot's IP reputation tool in front of my home router to see what kind of malicious traffic it was flagging. Here are the results.
The malware analysis team at F5 put together a great report on the Dridex malware. Here is me summarizes and mansplaining it.
“Is it possible to quantify your own security posture as it relates to denial-of-service? “ That’s the question a customer of ours has been asking themselves, and they came up with plan to measure exactly that. They’re going to DDoS their own production systems. And here's how they're going to do it.
The famous US patriot hacker, Th3J35t3r, posted his recipe for holiday cupcakes. I made them but it turned out they were full of malware.
A brief report of my experiences at DC12 in 2004.