Category: SANS

Do you want to learn how to ‘Blue Team’​? Start with “Time Based Security”​.

Posted on by Ismael Valenzuela

Also available on LinkedIn

“We’ve been looking at security the wrong way […] Fortress Mentality insists that building tall electronic walls is how to keep the bad guys out. That method hasn’t worked for 5000 years of warfare, so why should it work for computer security? It can’t and it doesn’t.” — Winn Schwartau.

As much as I love to put my red hat on, as I always explain to my SANS students, pentesting or even red teaming, can become ‘boring’ over time (sorry guys), especially when you are brought into environments where all the organization wants is to have a green check for yearly compliance purposes, or simply to have one more report to ignore. And trust me, that happens more often than not.

That is why I am so happy to see how many security professionals, experienced or not, are making the shift, joining the blue team ranks to learn how to defend their crown jewels in a highly increasingly complex world where technology advances so fast, data is ubiquitous, networks become more opaque and endpoint devices are less trusted than ever.

If this is your goal, and you are willing to get into an exciting, high paced but also highly rewarding field, where learning never stops… welcome aboard! Now, where do you start? There are a plethora of resources out there on how to get started into pentesting, but it seems that it is not so easy to find good resources on how to become an effective cyber defender.

There are many resources I can recommend, but since dropping here a list of 100 links won’t probably help you much, let me recommend you a very easy and light reading to start with: “Time Based Security”. Though it was written in 1999, TBS is still one of the most relevant, effective and terribly simple security models you can apply today. The principles enumerated in this book are absolutely essential for any blue teamer, regardless of whether you are a CISO, a SOC analyst, a security architect or an incident responder. TBS provides a reproducible method to understand how much ‘security’ a product or technology provides, by answering:

  • How long are systems exposed?
  • How long before we detect a compromise?
  • How long before we respond?

While it is usually applied to auditing, TBS is a very practical model to assess and design security architectures too. The method proposed is very simple, but it provides you with the knowledge and the tools required to make systems more secure and resilient. Here’s the main idea:

“If it takes longer to detect and to respond to an intrusion than the amount of protection time afforded by the security measures, that is if P < D + R then effective security is impossible to achieve in this system. It should be becoming a little bit obvious that the choice of a good protection system is not the first thing you need to think about when designing a secure network environment. It’s the efficacy of the detection and reaction processes that really matters.”

If this wasn’t good enough, Winn allows you to download and read his book for free on his website, so please go and grab a free copy of “Time Based Security” now!

https://winnschwartau.com/wp-content/uploads/2019/06/TimeBasedSecurity.pdf

Want to learn more on #BlueTeam? If so, please let me know, and I will follow up this post with a series of articles on how to improve your cyber defense skills. In the meantime check out the series of webinars that Justin Henderson and I recorded here:

Defensible Security Architecture and Engineering – Part 1: How to become an All-Round Defender – the Secret Sauce

Defensible Security Architecture and Engineering – Part 2: Thinking Red, Acting Blue – Mindset & Actions

Defensible Security Architecture and Engineering – Part 3: Protect your Lunch Money – Keeping the Thieves at Bay

Intelligence Driven Defense: Successfully Embedding Cyber Threat Intel in Security Operations

Posted on by Ismael Valenzuela

“I thought all I had to do was show the data and people would understand. It doesn’t work. You have to tell a story” – Cliff Stoll.

Easier said than done, right? Being able to tell a compelling story that can answer key questions like: who is attacking us, what is their motivation, were they here before, how do they operate, what is the impact to our business, and will they come back, should be one of the ultimate goals of any effective blue team. However, being successful at embedding cyber threat intel in SecOps require something else: maintaining a solid understanding of the environment we are defending, as well as a systematic way to identify and prioritize applicable threats and assess impact, so we can respond appropriately to these attacks.

In this talk, Ismael Valenzuela, Certified SANS Instructor and GSE #132, will share lessons learned and practical tips on how blue teams can not only consume but also produce actionable and contextual threat intelligence using tools, processes, models and taxonomies that are available to the community.

Slides:


Latest presos and blog posts: Malware traffic analysis with “Bro” and Catching “Bayas” on the wire

Posted on by Ismael Valenzuela

I don’t have to tell you how quickly life goes by. But I’m just amazed at the fact that it’s been more than 2 years without writing an entry in my blog! Not that I haven’t done anything interesting during this time though. Let me see… I moved to the “other side of the pond” (yup, that’s kind of a change!), I decided to take up my guitar lessons after many years… hey, I even took some cooking lessons for a few months! Hmm.. I wonder if this is a kind of pseudo early midlife crisis 🙂

Anyhow, on the professional side of things it’s been quite a productive time too. Although I already updated sections of my site to include some of this work, I wanted to share it here:

1. The slides from my talk “Catching Bayas on the Wire: Practical Kung-Fu to Detect Malware Traffic” presented at the 2013 SANS European Forensic Summit, are available on the Papers & Presentation page. A link to the updated version of this talk, presented in a BrightTalk Webinar on March 11th 2014 is there too.

2. My blog post “Identifying Malware Traffic with Bro and the Collective Intelligence Framework (CIF)” is posted on the Foundstone’s Open Security Research site. I’m specially happy and honoured to see that some of this work was more recently included in the latest version of the SANS 503: Intrusion Detection In-Depth class, after I had the privilege to teach the Bro section with Mike Poor and Judy Novak at SANS Orlando 2014. The pcap samples referenced in the post can be downloaded from my Github account.

3. More recently I was invited to participate as Guest Lecturer for the California Polytechnic State University in San Luis Obispo, teaching the Advanced Computer Forensic Methods & Tools class (part of the “Defense Against The Dark Arts” malware research course by McAfee/Intel Security). It was such a rewarding experience to teach to these motivated students!

Finally, I know quite a few people has been asking about Part 2 of the Android Memory Forensics post. Unfortunately something came up that prevented me from completing my work on this topic for more than a year. And by the time I had the opportunity to come back to this, so much had already changed that it didn’t make sense to continue writing the post along those lines. So my apologies for this. I promise I’ll get back to this topic, because it’s definitely a fascinating one.

Best I can probably do for now is to recommend a couple of good resources for you to check:

Talk to you soon!