Whids : Open Source EDR For Windows

Whids is a Open Source EDR For Windows with artifact collection driven by detection. The detection engine is built on top of a previous project Gene specially designed to match Windows events against user defined rules.

What do you mean by “artifact collection driven by detection” ?

It means that an alert can directly trigger some artifact collection (file, registry, process memory). This way you are sure you collected the artifacts as soon as you could (near real time).

All this work has been done on my free time in the hope it would help other people, I hope you will enjoy it. Unless I get some funding to further develop this project, I will continue developing it on a best effort basis. I will make all I can to fix issues in time and provide updates. Feel free to open issues to improve that project and keep it alive.

Why

• Provide an Open Source EDR to the community
• Make transparency on the detection rules to make analysts understand why a rule triggered
• Offer powerful detection primitives though a flexible rule engine
• Optimize Incident Response processes by drastically reducing the time between detection and artifact collection

How?

NB: the EDR agent can be ran standalone (without being connected to an EDR manager)

What you have to know

• It works only on Windows using ETW logs
• Relies on Sysmon for all the heavy lifting (kernel component)
• Very powerful and customizable detection engine (powered by gene)
• Built by an Incident Responder for all Incident Responders with the aim of making their job less painful
• Low footprint -> no process injection
• Can co-exist with any antivirus product (advised to run it along with MS Defender)
• Designed for high throughput. It can easily enrich and analyze up to 15M events a day per endpoint without performance impact. Good luck to achieve that with a SIEM.
• Easily integrable with other tools (Splunk, ELK, MISP …)
• Integrated with ATT&CK framework
• There is a powerful administrative API to ease management of large deployments (no GUI yet)

Installation

Requirements

1. Install Sysmon
2. Configure Sysmon
   • You can find optimized Sysmon configurations here
   • Logging any ProcessCreate and ProcessTerminate is mandatory
3. Take note of the path to your Sysmon binary because you will need it later on

NB: event filtering can be done at 100% with Gene rules so do not bother creating a complicated Sysmon configuration.

Pre-Installation Recommendations

In order to get the most of WHIDS you might want to improve your logging policy.

• Enable Powershell Module Logging
• Audit Service Creation: gpedit.msc -> Computer Configuration\Windows Settings\Security Settings\Advanced Audit Policy Configuration\System Audit Policies\System\Audit Security System Extension -> Enable
• Enable File System Audit. Sysmon only provides FileCreate events when new files are created, so if you want/need to log other kind of accesses (Read, Write, …) you need to enable FS Auditing.
  1. gpedit.msc -> Computer Configuration\Windows Settings\Security Settings\Advanced Audit Policy Configuration\System Audit Policies\Object Access\Audit File System -> Enable
  2. Right Click Any Folder -> Properties -> Security -> Advanced -> Auditing -> Add
     1. Select a principal (put here the name of the user/group you want the audit for). Put group Everyone if you want to log access from any user.
     2. Apply this to is used to select the scope of this audit policy starting from the folder you have selected
     3. Basic permissions select the kinds of accesses you want the logs to be generated for
     4. Validate
  3. File System auditing logs will appear in the Security log channel
• If you want an antivirus to run on your endpoints, keep Microsoft Defender, first because it is a good AV but also because it logs alerts in a dedicated log channel Microsoft-Windows-Windows Defender/Operational monitored by the EDR.

EDR Endpoint agent (Whids.exe)

This section covers the installation of the agent on the endpoint.

1. Download and extract the latest WHIDS release https://github.com/0xrawsec/whids/releases
2. Run manage.bat as administrator
3. Launch installation by selecting the appropriate option
4. Verify that files have been created at the installation directory
5. Edit configuration file by selecting the appropriate option in manage.bat or using your preferred text editor
6. Skip this if running with a connection to a manager, because rules will be updated automatically. If there is nothing in the rules directory the tool will be useless, so make sure there are some gene rules in there. Some rules are packaged with WHIDS and you will be prompted to choose if you want to install those or not. If you want the last up to date rules, you can get those here (take the compiled ones)
7. Start the services from appropriate option in manage.bat or just reboot (preferred option otherwise some enrichment fields will be incomplete leading to false alerts)
8. If you configured a manager do not forget to run it in order to receive alerts and dumps

NB: At installation time the Sysmon service will be made dependent of WHIDS service so that we are sure the EDR runs before Sysmon starts generating some events.

EDR Manager

The EDR manager can be installed on several platforms, pre-built binaries are provided for Windows, Linux and Darwin.

1. Create TLS certificate if needed for HTTPS connections
2. Create a configuration file (there is a command line argument to generate a basic config)
3. Run the binary

Configuration Examples

Please visit doc/configuration.md