Rapid7’s 2026 Global Cybersecurity Summit is now available on-demand.Watch sessions.
Rapid7

module

Variable-length Fnstenv/mov Dword XOR Encoder

Disclosed
N/A
Created
May 30, 2018

Description

This encoder uses a variable-length mov equivalent instruction
with fnstenv for getip.

Author

spoonm spoonm@no$email.com

Platform

All

Architectures

x86

Module Options

To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':


msf > use encoder/x86/fnstenv_mov
msf encoder(fnstenv_mov) > show actions
...actions...
msf encoder(fnstenv_mov) > set ACTION < action-name >
msf encoder(fnstenv_mov) > show options
...show and set options...
msf encoder(fnstenv_mov) > run

Title
Rapid7 Labs

2026 Global Threat Landscape Report

The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.