[satanonsteroids2024-zzz]

Describe your changes

Fixes #827.

python_job_func (task 112) execs module-supplied scripts inside a purpose-built globals dict containing only print:

output_capture = io.StringIO()
script_globals = {'print': lambda *a, **k: print(*a, **k, file=output_capture)}
try:
    exec(data, script_globals)

Several built-in modules stream output by calling job_message_buffer(msg) as a bare name from inside the script body they hand to the agent — python/collection/linux/xkeylogger, python/collection/linux/sniffer, python/collection/linux/port_scanner, and any custom module doing the same. Under the exec scope above the name is unresolved, so the script raises NameError, surfaced to the operator as:

[!] Error executing script: name 'job_message_buffer' is not defined

Separately (and this is what shapes the fix): MainAgent has both a string instance attribute self.job_message_buffer = "" (the accumulating buffer, set in __init__) and a method def job_message_buffer(self, message) with the same name. The instance attribute shadows the method, so even self.job_message_buffer(message) would raise 'str' object is not callable. That's a pre-existing tangle independent of this bug — left alone here rather than bundled into this fix.

Fix

Inject a small closure named job_message_buffer into script_globals that appends directly to the self.job_message_buffer string attribute, bypassing the shadowed method entirely:

def _append_job_message(msg):
    try:
        self.job_message_buffer += str(msg)
    except Exception as e:
        print("[!] Error adding job output to buffer: %s" % e, file=output_capture)

script_globals = {
    'print': lambda *a, **k: print(*a, **k, file=output_capture),
    'job_message_buffer': _append_job_message,
}

Only python_job_func is touched. get_job_message_buffer's existing flush-and-reset behavior on checkin is unchanged. dynamic_code_execute_wait_nosave (task 110) and dynamic_code_execution_wait_save (task 111) — the immediate-execute paths — don't run modules that stream via job_message_buffer, so they're untouched too.

Also added a CHANGELOG.md entry per the contribution checklist.

Verification

• python3 -m py_compile empire/server/data/agent/agent.py — compiles cleanly.
• Reproduced the exact exec-scope scenario in isolation (a standalone FakeAgent mirroring python_job_func's structure) with a script that calls job_message_buffer(msg) as a bare name, exactly like xkeylogger.yaml does: confirmed it previously raised NameError, and with the fix it correctly appends to the agent's real job_message_buffer string attribute with no exception.

Checklist before requesting a review

• I have performed a self-review of my code
• If it is a core feature, I have added thorough tests. (This is a scoped bugfix to existing background-job handling, not a new core feature; the existing test suite for MainAgent covers the surrounding paths.)
• I have added an entry to CHANGELOG.md
• I have updated the documentation in docs/ (not applicable — no user-facing behavior/interface change, just makes existing documented module behavior work)

Prepared with the assistance of Claude (Anthropic) for investigation and drafting; root cause and fix verified locally by me before submission.

[Cx01N]

Thanks @satanonsteroids2024-zzz! Your commit was cherry-picked (authorship preserved) into our development branch, then refined to bind the shadowed method and mirrored to the IronPython agent. It will ship here with the next release. Closing as superseded.