The staging function in the post/windows/powershell class was broken
in a previous commit as the definition for env_variable was removed and
env_prefix alone is now used. This caused an error to be thrown when
attempting to stage the payload. This changes the reference from
env_variable to env_prefix.
Additionally, the ps_wmi_exec module created a powershell script to be
run that was intended to be used with the EncodedCommand command line
option; however the script itself was never actually encoded. This
change passes the compressed script to the encode_script function to
resolve that issue.
Powershell::Script includes a random generator (@rig) which can
produce non repeating randomized identifiers to be used as var
names within the PSH code.
Unwrap script handling in powershell env stager to instantate a
method-local Powershell::Script object and access its :rig to
generate identifiers.
Initial check logic would compress any script, even those which
would not need it since an uncompressed script fitting the buffer
would likely fit compressed (unless its uncompressable and the
decoder stub overflows). Ensure that compression occurs only when
a compressed script would fit while the uncompressed one does not.
Replace variable names with generated strings to increase entropy.
Add compression test for stager to determine if a compressed PSH
script will fit into the allowed space. If so, compress and exec
without staging.
Add variable name cleanup to stager mechanism - Remove-Variable
with -ErrorAction SilentlyContinue is called on each stager var
name after the stager executes.
TODO: Update method documentation
Conflicts:
lib/msf/core/post/windows/powershell.rb
Rename upload_script_via_psh to stage_psh_env within post PSH lib.
Perform the same rename within load_script post module.
Brent Cook