Category Archives: Living off the land

Running programs via Proxy & jumping on a EDR-bypass trampoline, Part 2

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Update

After my post Zod contacted me with this mike-dropping link: Ultimate AppLocker ByPass List. Really lots of good stuff there! Thx Zod!

Old Post

In the first part I listed a couple of examples of programs that may be used as a proxy to launch other programs. In the meantime, subTee kicked off a very interesting thread on Twitter listing a number of signed .exe binaries that can be used as a proxy to load a DLL. Yesterday I came across a few cool posts by @0rbz_. This in return reminded me of my first post and I decided to add a few more proxy/living off the land ideas.

There is a number of signed .exe that can be used to load other .exes or .dlls and as a result – break standard EDR detection rules, or bypass some whitelisting. This may sometimes involve copying the signed binary to your folder in order to sideload your DLL (PlugX is a very good example, funnily enough – in many cases they don’t even need to bring a signed .exe and fetch one that is typically present on the system).

Here is the list:

  • AppVLP.exe – to launch .exe
    • From this Tweet by @0rbz_
    • Just run C:\Program Files\Microsoft Office\root\client\AppVLP.exe <exename>
  • pcalua.exe
    • From this Tweet by @0rbz_ and mentioned on this forum
    • Just run C:\windows\system32\pcalua.exe -a <exename>
  • odbcconf.exe – to load .dll
  • odbcad32.exe – to load .dll via GUI
    • drop c:\windows\system32\<dllfile>
    • run odbcad32.exe
    • go to Tracing Tab
    • choose Custom Trace DLL
    • hit Start Tracing Now
  • WinMail.exe – to load .dll
    • copy c:\Program Files\Windows Mail\WinMail.exe to your folder
    • name your DLL ‘msoe.dll’
    • launch one of these
      • WinMail.exe /identcatalog
      • WinMail.exe /identfileslist:foo
      • WinMail.exe /identfile:foo
  • xwizard.exe – to load .dll
    • From my previous post
    • copy c:\WINDOWS\system32\xwizard.exe to your folder
    • name your DLL ‘xwizards.dll’
    • run xwizard.exe with at least two arguments
  • java.exe – to load .dll
    • From my previous post
    • run java -agentlib:<dllname>
      or
    • run java -agentpath:<dllname_with_dll_extension>
  • any other phantom / sideloaded dlls – to load .dll

If you know of any other tricks like this, please let me know. Thanks!

p.s. as I was about to post it, Huntress Labs just published yet another cool technique using WseClientSvc.exe passthru.exe calc.exe!

The Wizard of X – Oppa PlugX style

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Xwizard is an ‘Extensible wizard host process’. While I am not 100% sure what it is doing I know for certain that – whatever it is – PlugX guys would approve.

Why?

When you run it with a ‘/h’ command line parameter, you will get this info:


Something about the unusual command line parameters described there caught my eye.

After a quick inspection I discovered why. The arguments are actually… names of functions exported from xwizards.dll!

Very nice!

And even nicer is the fact the LoadLibraryEx that loads that xwizards.dll finds its conveniently in the current path…

Ouch…

So… all you have to do is copy c:\WINDOWS\system32\xwizard.exe to your folder, drop your xwizards.dll DLL there and call xwizard.exe with at least two arguments.

And the Microsoft-signed xwizards.exe will load xwizards.dll of your choice…