Tag Archives: security

AWS ABCs – Can I Firewall My Compute Instances?

In a previous post, I reviewed what a public subnet and Internet Gateway (IGW) are and that they allowed outbound and inbound connectivity to instances (ie, virtual machines) running in the AWS cloud.

If you’re the least bit security conscious, your reaction might be, “No way! I can’t have my instances sitting right on the Internet without any protection”.

Fear not, reader. This post will explain the mechanisms that the Amazon Virtual Private Cloud (VPC) affords you to protect your instances.
Continue reading AWS ABCs – Can I Firewall My Compute Instances?

Explain Cisco ETA to Me in a Way That Even My Neighbor Can Understand It

Cisco Encrypted Traffic Analytics (ETA) sounds just a little bit like magic the first time you hear about it. Cisco is basically proposing that when you turn on ETA, your network can (magically!) detect malicious traffic (ie, malware, trojans, ransomware, etc) inside encrypted flows. Further, Cisco proposes that ETA can differentiate legitimate encrypted traffic from malicious encrypted traffic.

Uhmm, how?

The immediate mental model that springs to mind is that of a web proxy that intercepts HTTP traffic. In order to intercept TLS-encrypted HTTPS traffic, there’s a complicated dance that has to happen around building a Certificate Authority, distributing the CA’s public certificate to every device that will connect through the proxy and then actually configuring the endpoints and/or network to push the HTTPS traffic to the proxy. This is often referred to as “man-in-the-middle” (MiTM) because the proxy actually breaks into the encrypted session between the client and the server. In the end, the proxy has access to the clear-text communication.

Is ETA using a similar method and breaking into the encrypted session?

In this article, I’m going to use an analogy to describe how ETA does what it does. Afterwards, you should feel more comfortable about how ETA works and not be worried about any magic taking place in your network. 🧙

Continue reading Explain Cisco ETA to Me in a Way That Even My Neighbor Can Understand It

So Your Username and Password Where in a Data Dump. Now What?

Whether it’s Dropbox, LinkedIn, MySpace, PlayStation, or whatever the latest breach happens to be, it’s almost inevitable that you will be caught up in one of these breaches and have your username, password and possibly other information exposed in a data dump. Here’s how to respond when that happens. Continue reading So Your Username and Password Where in a Data Dump. Now What?

SSH Agent on OS X

There’s a lot of information on the intertoobs about getting ssh-agent “working” in OS X and even more articles about when and how the stock behavior of ssh-agent changed (mostly with respect to how ssh-agent interacted with the Keychain).

This article doesn’t cover or care about any of that.

This article is concerned with:

  • Enabling ssh-agent in such a way that I can “ssh-add” in one terminal window and that same agent (and the loaded keys) is available in all of my other terminal windows.
  • Enabling use of ssh-agent from MacPorts and/or Homebrew and not the older ssh-agent that OS X ships with in /usr/bin.
  • To avoid having to put my keys in the Keychain (just a matter of preference).

Continue reading SSH Agent on OS X

Auto Renew Let’s Encrypt Certificates

I’m a big fan of Let’s Encrypt (free, widely trusted SSL certificates) but not a big fan of most of the client software available for requesting and renewing certificates. Unlike a typical certificate authority, Let’s Encrypt doesn’t have a webui for requesting/renewing certs; everything is driven via an automated process that is run between a Let’s Encrypt software client and the Let’s Encrypt web service.

Since the protocols that Let’s Encrypt uses are standards-based, there are many open source clients available. Being security conscious, I have a few concerns with most of the clients:

  • Complication. Many of the clients are hundreds of lines long and unnecessarily complicated. This makes the code really hard to audit and since this code is playing with my crypto key material, I do want to audit it.
  • Elevated privilege. At least one of the clients I saw required root permission. That’s a non starter.

Continue reading Auto Renew Let’s Encrypt Certificates

Getting Traffic to a Virtual Firepower Sensor

I wanted to jot down some quick notes relating to running a virtual Firepower sensor on ESXi and how to validate that all the settings are correct for getting traffic from the physical network down into the sensor.

Firepower is the name of Cisco’s (formerly Sourcefire’s) so-called Next-Gen IPS. The IPS comes in many form-factors, including beefy physical appliances, integrated into the ASA firewall, and as a discrete virtual machine.

Since the virtual machine (likely) does not sit in-line of the traffic that needs to be monitored, traffic needs to be fed into the VM via some method such as a SPAN port or a tap of some sort.

Continue reading Getting Traffic to a Virtual Firepower Sensor

Five Functional Facts about TACACS+ in ISE 2.0

The oft-requested and long awaited arrival of TACACS+ support in Cisco’s Identity Services Engine (ISE) is finally here starting in version 2.0. I’ve been able to play with this feature in the lab and wanted to blog about it so that existing ISE and ACS (Cisco’s Access Control Server, the long-time defacto TACACS+ server) users know what to expect.

Below are five facts about how TACACS+ works in ISE 2.0.

Continue reading Five Functional Facts about TACACS+ in ISE 2.0

Packets of Interest (2015-06-19)

It’s been a while since I’ve done a POI so here we go.

The Mystery of Duqu 2.0: a sophisticated cyberespionage actor returns

https://securelist.com/blog/research/70504/the-mystery-of-duqu-2-0-a-sophisticated-cyberespionage-actor-returns/

Kaspersky Lab found this new variant of the Duqu malware in their own network. They wrote a paper based on their analysis of this new malware. It fascinates me how sophisticated these software packages are and how much effort the threat actors put into them.

Diffie-Hellman Key Exchange

Diffie-Hellman (DH) is the world’s first public key crypto system. It’s used in everything from secure browsing, to secure shell. This video visually demonstrates how the Diffie-Hellman key exchange works. The best part is that you don’t need to know anything about crypto to follow along.

Passphrases That You Can Memorize – But That Even the NSA Can’t Guess

https://firstlook.org/theintercept/2015/03/26/passphrases-can-memorize-attackers-cant-guess/

Use this informative guide to generate secure, human-memorizable passphrases that are suitable for protecting your private PGP key, your private SSH key, and your master key for your password safe.

Encrypting Your Laptop Like You Mean It

https://firstlook.org/theintercept/2015/04/27/encrypting-laptop-like-mean/

A well written article about encrypting one’s laptop. Covers topics such as what disk encryption does and does not protect against, attacks against disk encryption, and then encrypting disks in Windows and OS X.

BRKSEC-2010: Emerging Threats – The State of Cyber Security

Presenter: Craig Williams (@security_craig) – Sr Technical Leader / Security Outreach Manager, Cisco TALOS

I’m from Talos. We love to stop bad guys.

 
Talos by the numbers:

  • 1.1 million incoming malware samples per day
  • 1.5 billion Sender Base reputation queries per day

Talos has a serious amount of data. For serious.
Continue reading BRKSEC-2010: Emerging Threats – The State of Cyber Security