TaoSecurity Blog

At the end of the 1973 Clint Eastwood movie Magnum Force , after Dirty Harry watches his corrupt police captain explode in a car, he says "a man's got to know his limitations." I thought of this quote today as the debate rages about compromising municipalities and other information technology-constrained yet personal information-rich organizations. Several years ago I wrote If You Can't Protect It, Don't Collect It . I argued that if you are unable to defend personal information, then you should not gather and store it. In a similar spirit, here I argue that if you are unable to securely operate information technology that matters, then you should not be supporting that IT . You should outsource it to a trustworthy cloud provider , and concentrate on managing secure access to those services. If you cannot outsource it, and you remain incapable of defending it natively, then you should integrate a capable managed security provider . It's clear to ...

I was investigating traffic in my home lab yesterday, and noticed that about 1% of the traffic was weird. Before I describe the weird, let me show you a normal frame for comparison's sake. This is a normal frame with Ethernet II encapsulation. It begins with 6 bytes of the destination MAC address, 6 bytes of the source MAC address, and 2 bytes of an Ethertype, which in this case is 0x0800, indicating an IP packet follows the Ethernet header. There is no TCP payload as this is an ACK segment. You can also see this in Tshark. $ tshark -Vx -r frame4238.pcap Frame 1: 66 bytes on wire (528 bits), 66 bytes captured (528 bits)     Encapsulation type: Ethernet (1)     Arrival Time: May  7, 2019 18:19:10.071831000 UTC     [Time shift for this packet: 0.000000000 seconds]     Epoch Time: 1557253150.071831000 seconds     [Time delta from previous captured frame: 0.000000000 seconds]     [Time delta from previous di...

I spent a chunk of the day troubleshooting a network security monitoring (NSM) problem. I thought I would share the problem and my investigation in the hopes that it might help others. The specifics are probably less important than the general approach. It began with ja3 . You may know ja3 as a set of Zeek scripts developed by the Salesforce engineering team to profile client and server TLS parameters. I was reviewing Zeek logs captured by my Corelight appliance and by one of my lab sensors running Security Onion. I had coverage of the same endpoint in both sensors. I noticed that the SO Zeek logs did not have ja3 hashes in the ssl.log entries. Both sensors did have ja3s hashes. My first thought was that SO was misconfigured somehow to not record ja3 hashes. I quickly dismissed that, because it made no sense. Besides, verifying that intution required me to start troubleshooting near the top of the software stack. I decided to start at the bottom, or close to the bottom. I ha...

Last week I attended my first OSSEC conference. I first blogged about OSSEC in 2007, and wrote other posts about it in the following years. OSSEC is a host-based intrusion detection and log analysis system with correlation and active response features. It is cross-platform, such that I can run it on my Windows and Linux systems. The moving force behind the conference was a company local to me called Atomicorp . In brief, I really enjoyed this one-day event. (I had planned to attend the workshop on the second day but my schedule did not cooperate.) The talks were almost uniformly excellent and informative. I even had a chance to talk jiu-jitsu with OSSEC creator Daniel Cid, who despite hurting his leg managed to travel across the country to deliver the keynote. I'd like to share a few highlights from my notes. First, I had been worried that OSSEC was in some ways dead. I saw that the Security Onion project had replaced OSSEC with a fork called Wazuh, which I learned is a...

Recently I've been reading about cloud security and security with respect to DevOps. I'll say more about the excellent book I'm reading, but I had a moment of déjà vu during one section. The book described how cloud security is a big change from enterprise security because it relies less on IP-address-centric controls and more on users and groups. The book talked about creating security groups, and adding users to those groups in order to control their access and capabilities. As I read that passage, it reminded me of a time long ago, in the late 1990s, when I was studying for the MCSE, then called the Microsoft Certified Systems Engineer. I read the book at left, Windows NT Security Handbook, published in 1996 by Tom Sheldon. It described the exact same security process of creating security groups and adding users. This was core to the new NT 4 role based access control (RBAC) implementation. Now, fast forward a few years, or all the way to today, and consider the ...

Jack Crook  pointed me toward a story by  Christopher Burgess  about intellectual property theft by "Hongjin Tan, a 35 year old Chinese national and U.S. legal permanent resident... [who] was arrested on December 20 and charged with theft of trade secrets. Tan is alleged to have stolen the trade secrets from his employer, a U.S. petroleum company," according to the criminal complaint filed by the US DoJ. Tan's former employer and the FBI allege that Tan "downloaded restricted files to a personal thumb drive." I could not tell from the complaint if Tan downloaded the files at work or at home, but the thumb drive ended up at Tan's home. His employer asked Tan to bring it to their office, which Tan did. However, he had deleted all the files from the drive. Tan's employer recovered the files using commercially available forensic software. This incident, by definition, involves an "insider threat." Tan was an employee who appears to have cop...

Yesterday I posted about DetectionLab , but noted that I was having trouble with the RDP servers offered by Virtualbox. If you remember, DetectionLab builds four virtual machines: root@LAPTOP-HT4TGVCP C:\Users\root> "c:\Program Files\Oracle\VirtualBox\VBoxManage" list runningvms "logger" {3da9fffb-4b02-4e57-a592-dd2322f14245} "dc.windomain.local" {ef32d493-845c-45dc-aff7-3a86d9c590cd} "wef.windomain.local" {7cd008b7-c6e0-421d-9655-8f92ec98d9d7} "win10.windomain.local" {acf413fb-6358-44df-ab9f-cc7767ed32bd} I was having a problem with two of the VMs sharing the same port for the RDP server offered by Virtualbox. This meant I could not access one of them. (Below, port 5932 has the conflict.) root@LAPTOP-HT4TGVCP C:\Users\root\git\detectionlab\DetectionLab\Vagrant> "c:\Program Files\Oracle\VirtualBox\VBoxManage" showvminfo logger | findstr /I vrde  | findstr /I address VRDE:                        enabled (Ad...