S4E3: "Insane in the Mainframe"

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Recorded (UTC) Aired (UTC) Editor
2019-03-21 02:57:44 2019-03-31 19:27:30 "Edita"
Format SHA256 GPG Audio File
MP3 aef620f7e80481a26010b9c39c8dfcc6d5e75669fa6c8241e17e1ef4d82cde8a click click
OGG 2e30eb7f18551e4d1e71ed71a0ad059f1b5c7d7d89ea8c681cd2f60a17d0fd2a click click

We have Phil (@mainframed767) on to talk about mainframes. Yes, they’re still being used and yes, they’re modern implementations.

Just the Tip

  • An introduction to LXC (Linux Containers)
    • He mentions haveged (pronounced “have G-E-D” or, if I’m in a rush, I say “have ged”)
      • The SuperUser question I answered (I said StackOverflow, oops; same network) is here. Why it was downvoted, I’ll never know.
    • He also mentions an optional dependency is dnsmasq, which we’ve mentioned more than once on the show before.
    • LXC is basically a cross between a virtualization (VM) and a chroot.
      • Know what OpenVZ/Virtuozzo is? Yeah, basically that.
    • LXC used to be the driving technology behind Docker (but as of Docker 0.9, Docker replaced LXC with libcontainer).
    • The kernel capabilities I mention can be found here.
      • You can find documentation on how to grant these capabilities in a Systemd unit here.


Starts at 8m56s.

I was drinking a Guinness Extra Stout. Paden was drinking Absolut and Glenmorangie again. Jthan was drinking a lime Spindrift. Phil was drinking Highland Park 18-Year.

  • Mainframes in the modern era!
    • Mainframes are not only still used, they are modern and integral to modern global/enterprise business.
    • Phil mentions Connor buying a used mainframe. You can find his talk here.
    • You can find access to the DISA STIGs here.
      • And mainframe-specific STIGs are here.
    • DES is a really bad idea, but many mainframe logins still use it…
      • The Baddie that was mentioned is S1E18. The solution was given in S1E21.
    • Patching in mainframes is typically pretty obfuscated/obtuse.
  • You can find more about Phil (Soldier of Fortran) and mainframes here:
    • His talks
    • The talk I’ve seen and referenced (Mainframe hacking)
    • The IMP (Internet Mainframes Project) is here.
    • His PoC||GTFO contributions (we have a mirror here):
      • #12, A JCL Adventure with Network Job Entries
      • #17, Murder on the USS Table
    • His blog is here.
    • Another mainframe hacker mentioned a lot, Chad, has a mainframe-hacking blog here.
    • He and Chad also offer mainframe pentesting classes, which you can find here.
      • Mainframe pentesting is still pretty niche; they need all the passionate pentesters they can get!
    • He mentioned the Logica breach
    • The z/OS emulator he mentions is here
      • and an opensource full-stack (running an older mainframe OS), called Hercules, is here.
    • He also recommends this z/OS on Hercules guide.

15 Clams

In this segment, Jthan shares with you a little slice of life. The title is a reference to this video. (2m16s in)

Starts at 1h12m35s.

Jthan ponders whether it’s “better”, in terms of what you learn/experience, to work for a big enterprise or small business.

Interestingly, shortly after we talked about it, I found a nice summation/thread on Twitter of why the question may not have a direct answer.


  • Contrary to what Paden said about LXC, you do NOT need to run/start libvirtd to use LXC – this is only necessary if you’re using LXC as a backend for libvirtd.
  • To give some context, this episode was recorded roughly a week after Facebook had a severe outage.
  • Sure enough, on March 28 and March 31, new PoC||GTFO issues are in digital format and have made it to our mirror. :)
  • The CIA sabotage manual is indeed still available.


Music Credits
Track Title Artist Link Copyright/License
Intro Truckin Bio Unit/Metre click CC-BY-NC-SA 4.0
Outro The Opening Closing P C III click CC-BY 4.0
(All music is royalty-free, properly licensed for use, used under fair use, or public domain.)



  1. Awesome episode!

  2. mouath- thanks! glad to have you listening!

  3. Great episode. A small portion of my daily life is supporting zPDT (the emulated development environment for z/OS) and your guest gave a lot of great information about the attack surface of these systems. Also good to know that there are people dedicated to breaking into them; it’s easy to assume that mainframe security doesn’t need care and feeding because “none of the bad guys would even know where to start with them.”

  4. tim- thanks! i’m sure Phil would be glad to hear your support!


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