RAT Client wont connect

[28]

Hello everyone,

I am currently trying to infect a pc with a rat.
I have access to the pc so antivirus shouldnt be a problem.

However I cannot get my client to connect to my server.

I've done the following:
rented a vps on crazyrdp
downloaded EagleMonitor from Github
build a simple client with no extra features and with the IP from my VPS

When I am starting the .exe on the vps I can infect myselft and everything works.
But as soon as I am trying it outside the vps in a VM for example I simply never get a connection
no matter what I do.
I also tried it with another rat, same thing there. So I dont think the rat is broken, its rather a setting I am missing
I guess.

Any ideas on what I should do better?

[27]

check ports. make sure its a open port

[28]

check ports. make sure its a open port

Can you explain this a bit more in detail?
When checking ports on https://portchecker.co on the VPS it seems only port 3389 is open.
And when checking on the test VM to infect it seems like all ports are closed.
Even though I am connected with the VPS so shouldnt also atleast be port 3389 open?

[27]

try different port like 2888