SILENTTRINITY VS Empire

You're certainly right that it doesn't need an XML extension. But it also frequently will due to many tools using it by default (e.g. line 13 in https://github.com/byt3bl33d3r/SILENTTRINITY/blob/master/silenttrinity/core/teamserver/stagers/msbuild.py).

Is the new version. The original Empire one was discontinued Old: https://github.com/EmpireProject/Empire New: https://github.com/BC-SECURITY/Empire

C# for Windows, EDR bypassing. Windows API and native API calls, undocumented API calls and similar. Look at things like this blog here https://www.inversecos.com/2022/03/windows-event-log-evasion-via-native.html and other resources such as the Windows Internals. Sektor7 would be good with their AV bypass courses, but I have only heard of reviews being good, but not done the courses so DYOR. Try the PentesterAcademy courses on Windows. PowerShell pentesting. Frameworks like Empire in Kali, https://www.kali.org/tools/powershell-empire/ && https://github.com/BC-SECURITY/Empire

First of all, Empire4 is a post-exploitation framework, such as Cobalt Strike, Covenant or Meterpreter. It actually rely a lot on Meterpreter, as I will explain later. This means it allows you to deploy listeners in your server and configure attacks connected to them. Empire itself was active for so many years and became deprecated, then Empire4 came up using updated resources. It's open source and it's used for both threat actors (cybercriminals) and offensive security auditors, as well as students of course.

Empire: https://github.com/BC-SECURITY/Empire/

Unless I am mistaken it is being maintained here by another team. They are also working on a frontend for it called Starkiller. https://github.com/BC-SECURITY/Empire

Metasploit and Merlin are the larger post-exploitation frameworks that come to mind. As an FYI there's a forked version of Empire now actively in development too - https://github.com/BC-SECURITY/Empire.