MalwLess Simulation Tool (MST)

MalwLess is an open source tool that allows you to simulate system compromise or attack behaviours without running processes or PoCs. The tool is designed to test Blue Team detections and SIEM correlation rules. It provides a framework based on rules that anyone can write, so when a new technique or attack comes out you can write your own rules and share it a with the community.

These rules can simulate Sysmon or PowerShell events. MalwLess can parse the rules and write them directly to the Windows EventLog, then you can foward it to your event collector.

MalwLess Simulation Tool v1.1
Author: @n0dec
Site: https://github.com/n0dec/MalwLess

[Rule test file]: rule_test.json
[Rule test name]: MalwLess default
[Rule test version]: 0.3
[Rule test author]: n0dec
[Rule test description]: MalwLess default test pack.

[>] Detected rule: rules.vssadmin_delete_shadows
... Source: Sysmon
... Category: Process Create
... Description: Deleted shadows copies via vssadmin.
[>] Detected rule: rules.certutil_network_activity
... Source: Sysmon
... Category: Network connection detected
... Description: Network activity from certutil tool.
[>] Detected rule: rules.powershell_scriptblock
... Source: PowerShell
... Category: 4104
... Description: Powershell 4104 event for Invoke-Mimikatz.

Download

You can download the latest release from website https://n0dec.github.io/#malwless

or from releases section https://github.com/n0dec/MalwLess/releases

Usage

Requirements

It is necessary to have sysmon installed in your system. https://docs.microsoft.com/en-us/sysinternals/downloads/sysmon

Commands

When you have downloaded the latest release version you can run it directly from an elevated command prompt.

To test the default rule set which is on rule_test.json just download it and run:

> malwless.exe

If you want to test a different rule set file, use the -r parameter:

> malwless.exe -r your_pack.json

To write a custom rule set check the writing sets section.

Creating rules

Anyone can create a rule. These are written in json with an easy format. Additionally you can parse raw events and convert it to rule using converter

key	values
enabled	If the value is set to true the event will be written. If it's set to false just ignore the rule.
source	Sysmon PowerShell
category	For each source there are a list of different categories that can be specified.
description	A simple rule description.
payload	These are the values that will be added to the event. If you don't indicate a specific payload the event will contain the values of the default configuration files located on conf.

Rule example

  "process_create_rule": {
    "enabled": true,
    "source": "Sysmon",
    "category": "Process Create",
    "description": "Activity event based on Process Create category.",
    "payload": {
      "Image": "process.exe",
      "CommandLine": "process.exe --help"
    }
  }

Sets

• Mitre ATT&CK ref: https://attack.mitre.org/
• APTSimulator set ref: https://github.com/NextronSystems/APTSimulator
• Endgame RTA set ref: https://github.com/endgameinc/RTA
• Windows oneliners ref: https://arno0x0x.wordpress.com/2017/11/20/windows-oneliners-to-download-remote-payload-and-execute-arbitrary-code/
• WinPwnage set ref: https://github.com/rootm0s/WinPwnage
• Awesome gists sets

Contact

For any issue or suggestions contact me on twitter @n0dec.

Website: https://n0dec.github.io