@6a7070 There hasn't been extensive testing for anything below Python 2.7. Do any of the modules return output? Have you tried any other commands? On the agent side the best place to debug is to just add a print statement here: https://github.com/EmpireProject/Empire/blob/master/data/agent/agent.py#L260 . Print out the value of resultData for shell commands. I'll see if I can get a python 2.6 environment setup and test.
Thanks.

Thank you @xorrior for the help! It made it much easier to figure out a solution!

I figured out that the encode() function in Python 2.6.6 cannot include any keyword arguments like "errors". The command output from the agent never gets sent to the Empire server because the agent errors out. Specifically line 136 (https://github.com/EmpireProject/Empire/blob/master/data/agent/agent.py#L136) causes the error:

    packetData = base64.b64encode(packetData.decode('utf-8').encode('utf-8',errors='ignore'))
TypeError: encode() takes no keyword arguments

If line 136 is replaced with the following code, then the agent can encode the packetData and send it to the Empire server and display it to the operator.
packetData = base64.b64encode(packetData.decode('utf-8').encode('utf-8','ignore'))

I did further research into the differences between Python 2.6 and 2.7. Turns out that Python 2.7 added support for "keyword" arguments to the the encode function. https://docs.python.org/release/2.7.5/library/stdtypes.html?highlight=encode#str.encode

I tested the modified line 136 with agents running Python 2.6.6 and 2.7.5, both worked.

I don't think the original code meant to use the keyword argument of 'errors', because it isn't necessary to ignore errors during encoding. The modified code should successfully ignore any issues. https://docs.python.org/2/howto/unicode.html

It seems to be safe to make this change to the Python agent and it will support both 2.7 and 2.6.

Is this a change you would be willing to add to Empire?

@6a7070 Sure, would you mind creating a PR for this? :)

@6a7070 fixed in the dev branch. Sorry for the wait.

Thank you for making this change and keep track of it!