Psiphon (#1771)

* message

* Update T1090.003.yaml

* Final updates b4 merge

Removed input arg, split dependencies out into two different ones, made use of USERPROFILE environment variable to improve robustness of test.

* use %USERPROFILE% environment variable

Co-authored-by: Chase James <cjames@nti.local>
Co-authored-by: Carrie Roberts <clr2of8@gmail.com>

atomics/T1090.003/T1090.003.yaml

@@ -0,0 +1,37 @@
+attack_technique: T1090.003
+display_name: 'Proxy: Multi-hop Proxy'
+atomic_tests:
+- name: Psiphon
+  description: |
+    Psiphon 3 is a circumvention tool from Psiphon Inc. that utilizes VPN, SSH and HTTP Proxy technology to provide you
+    with uncensored access to Internet.
+    This process will launch Psiphon 3 and establish a connection. Shortly after it will be shut down via process kill commands.
+    More information can be found about Psiphon using the following urls
+    http://s3.amazonaws.com/0ubz-2q11-gi9y/en.html
+    https://psiphon.ca/faq.html
+  supported_platforms:
+    - windows
+  dependency_executor_name: powershell 
+  dependencies:
+    - description: |
+        The proxy settings backup file must exist on disk at $env:Temp\proxy-backup.txt
+      prereq_command: | 
+        if (Test-Path $env:Temp\proxy-backup.txt) {exit 0} else {exit 1}
+      get_prereq_command: |
+        if(-not (test-path $env:Temp\proxy-backup.txt)){
+        $Proxy = (Get-ItemProperty -Path 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings' -Name "ProxyServer" -ErrorAction Ignore).ProxyServer
+        Set-Content $env:Temp\proxy-backup.txt $Proxy}
+    - description: |
+        The Psiphon executable must exist in the Downloads folder
+      prereq_command: | 
+        if (Test-Path $env:UserProfile\Downloads\psiphon3.exe) {exit 0} else {exit 1}
+      get_prereq_command: |
+        Invoke-WebRequest -OutFile "$env:UserProfile\Downloads\psiphon3.exe" "https://s3.amazonaws.com/0ubz-2q11-gi9y/psiphon3.exe"
+  executor:
+    name: powershell
+    command: |
+      PathToAtomicsFolder\T1090.003\src\Psiphon.bat
+    cleanup_command: |
+      $Proxy = Get-Content $env:Temp\proxy-backup.txt -ErrorAction Ignore
+      if($null -ne $Proxy) 
+      {Set-ItemProperty -Path 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings' -Name "ProxyServer" -Value $Proxy}

atomics/T1090.003/src/Psiphon.bat

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+@echo off
+start %USERPROFILE%\Downloads\psiphon3.exe
+timeout /t 20 >nul 2>&1
+Taskkill /IM msedge.exe /F >nul 2>&1
+Taskkill /IM psiphon3.exe /F >nul 2>&1
+Taskkill /IM psiphon-tunnel-core.exe /F >nul 2>&1