A small discovery about AppLocker

While I was prepping for a session a while back I made a a little special discovery about AppLocker. Turns out that the files that AppLocker uses under C:\Windows\System32\AppLocker can be used in many cases to bypass a Default AppLocker ruleset. When a machine is deployed and the first user logs in, that user will … Continue reading A small discovery about AppLocker

Bypassing AppLocker as an admin

I thought it would be useful to have a blog post about two different techniques you can use to bypass AppLocker if you are an admin on a host that has AppLocker enabled. The first technique that uses the GUI was briefly discussed in a tweet I posted a while back: https://twitter.com/Oddvarmoe/status/996147947975962624  My goal with this … Continue reading Bypassing AppLocker as an admin

%Temp%orary Constrained Language mode in AppLocker

TL;DR Done as a normal user without admin privs Change %TEMP%/%TMP% to point to a location that allows execution of scripts defined by AppLocker Start Powershell with the new environment variables that you set for %TEMP%/%TMP% and profit! Background This blogpost covers a technique I discovered when digging further into AppLocker to bypass Powershell Constrained … Continue reading %Temp%orary Constrained Language mode in AppLocker

AppLocker – Making sure that local rules are removed

This is just a quick blogpost about a thing I forgot to write about a long time ago. One issue with AppLocker is that when someone gets admin access on a box they can create local AppLocker rules that will be combined with the Group Policy AppLocker rules. This is explained in this tweet here: https://twitter.com/Oddvarmoe/status/996147947975962624 … Continue reading AppLocker – Making sure that local rules are removed

Persistence using Universal Windows Platform apps (APPX)

TL;DR Persistence can be achieved with Appx/UWP apps using the debugger options. This technique will not be visible by Autoruns. Two different approaches exists (registry keys). Listed below are the two techniques for two different apps that starts at logon: Cortana app: reg add HKCU\Software\Microsoft\Windows\CurrentVersion\PackagedAppXDebug\Microsoft.Windows.Cortana_1.10.7.17134_neutral_neutral_cw5n1h2txyewy /d "C:\windows\system32\cmd.exe" OR reg add HKCU\Software\Classes\ActivatableClasses\Package\Microsoft.Windows.Cortana_1.10.7.17134_neutral_neutral_cw5n1h2txyewy\DebugInformation\CortanaUI.AppXy7vb4pc2dr3kc93kfc509b1d0arkfb2x.mca /v DebugPath /d "C:\windows\system32\cmd.exe" … Continue reading Persistence using Universal Windows Platform apps (APPX)

Another way to get to a system shell – Assistive Technology

TL;DR Manipulate HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Accessibility\ATs\magnifier - StartExe to run other binary when pressing WinKey and plus to zoom. Can load binary from Webdav and also start webbrowser and browse to desired link Runs command as system during UAC prompt and logon screen   I have thought a while about this blogpost and finally had some time to … Continue reading Another way to get to a system shell – Assistive Technology

Real whitelisting attempt using AppLocker

I wanted to try and see if I was able to use AppLocker to only allow needed files (Real whitelisting). Normally what you would do when setting up AppLocker is that you would start out by trusting something. This something could either be everything under C:\windows and c:\programfiles, or it could be every file that … Continue reading Real whitelisting attempt using AppLocker