Covenant v0.6 releases: a .NET command and control framework

by do son · Published August 26, 2019 · Updated January 29, 2023

Covenant

Covenant is a .NET command and control framework that aims to highlight the attack surface of .NET, make the use of offensive .NET tradecraft easier, and serve as a collaborative command and control platform for red teamers.

Covenant is an ASP.NET Core, cross-platform application that includes a robust API to enable a client-server architecture that allows for multi-user collaboration. There are three main components of Covenant’s architecture:

Covenant – Covenant is the server-side component of the client-server architecture. Covenant runs the command and control server hosted on infrastructure shared between operators. I will also frequently use the term “Covenant” to refer to the entire overarching project that includes all components of the architecture.
Elite – Elite is the client-side component of the client-server architecture. Elite is a command-line interface that operators use to interact with the Covenant server to conduct operations.
Grunt – A “Grunt” is the name of Covenant’s implant that is deployed to targets.

Features

Covenant has several key features:

Multi-Platform – Covenant and Elite both target .NET Core, which makes them multi-platform. This allows these programs to run natively on Linux, MacOS, and Windows platforms. Additionally, both Covenant and Elite have docker support, allowing these programs to run within a container on any system that has docker installed.
Multi-User – Covenant supports multi-user collaboration. The ability to collaborate has become crucial for effective red team operations. Many users can start Elite clients that connect to the same Covenant server and operate independently or collaboratively.
API Driven – Covenant is driven by a server-side API that enables multi-user collaboration and is easily extendible. Additionally, Covenant includes a Swagger UI that makes development and debugging easier and more convenient.
Listener Profiles – Covenant supports listener “profiles” that control how the network communication between Grunt implants and Covenant listeners look on the wire.
Encrypted Key Exchange – Covenant implements an encrypted key exchange between Grunt implants and Covenant listeners that is largely based on a similar exchange in the Empire project, in addition to optional SSL encryption. This achieves the cryptographic property of forwarding secrecy between Grunt implants.
Dynamic Compilation – Covenant uses the Roslyn API for dynamic C# compilation. Every time a new Grunt is generated or a new task is assigned, the relevant code is recompiled and obfuscated with ConfuserEx, avoiding totally static payloads. Covenant reuses much of the compilation code from the SharpGen project, which I described in much more detail in a previous post.
Inline C# Execution – Covenant borrows code and ideas from both the SharpGen and SharpShell projects to allow operators to execute C# one-liners on Grunt implants. This allows for similar functionality to that described in the SharpShell post but allows the one-liners to be executed on remote implants.
Tracking Indicators – Covenant tracks “indicators” throughout the operation, and summarizes them in the Indicators menu. This allows an operator to conduct actions that are tracked throughout an operation and easily summarize those actions to the blue team during or at the end of an assessment for deconfliction and educational purposes. This feature is still in its infancy and still has room for improvement.

Changelog

[v0.6] – 2020-08-04

Added

Added CreateDirectory task
Add SharpSC submodule, ReferenceSourceLibrary, and GruntTask
Added CreateProcessWithToken task
Added aliases for Shell tasks
Added ShellCodeLauncher using Donut
Added Copy command
Added missing Keylogger task
Added streaming task output
Added Download/Upload .NET Core Tasks
Added ReadTextFile,CreateDirectory,Delete .NET Core Tasks
Added UI Themes, new Heathen Mode theme
Added a TabbedTerminal view to GruntIndex component
Added message that Covenant has started

Changed

Add SharpSploit.LateralMovement namespace to SharpShell command
Updated PowerShellRemoting tasks to show output
Update implants to use WellKnownSidType enum rather than string for non-english systems
Update all launchers to support non-http profiles
Changed Shell tasks to use CreateProcess to get output
Updated SharpSploit, Rubeus, Seatbelt ReferenceSourceLibaries to latest versions
Simplified compilation optimization to use HashSet
Limited compilation optimization for SharpSC
Updated Seatbelt to latest version
Updated SharpSploit to latest version, PowerShell task should include verbose/error output
Changed GruntTask export to exclude GruntTaskOption value property
Updated codemirror, added night theme for codemirror
Removed Covenant certificate hash message

Fixed

Fixed order of Upload parameters
Fixed Brute compilation path for case-sensitive file systems
Fixed HttpPost issue on Linux servers
Fixed Listeners stop issue
Fixed Seatbelt command group suggestions
Fixed EditGruntTask for task with aliases, validationmessage issue
Fixed Task aliases to be able to be edited
Fixed InstallUtil launcher
Fixed PowerShellLauncher maxlength too short
Fixed BridgeListener null exception on creation
Fixed Dockerfile to use sdk for runtime
Fixed ordering of deserialized GruntTask Options
Fixed Assembly tasks to do command-line style parsing
Updated YAML task file code options to use literal strings, may have been causing some problems
Fixed parameter parsing bug when multiple trailing double-quotes
Fixed command parameter parsing bug when multiple trailing double-quotes
Fixed command parameter parsing bug when labeled parameter
Fixed CovenantUser default properties set to null, not following OpenApi spec
Fixed task aliases use incorrect case comparisons
Fixed LauncherForm exception when no active listeners
Fixed missing ReferenceAssemblies for SharpSploit
Fixed WMICommand/WMIGrunt output format
Fixed ConnectAttempts bug
Fixed BridgeListener ArgumentOutOfRangeException
Fix/tweak Connect/Disconnect tasks
Fixed JwtKey issue
Fixed ImplantTemplateForm options resetting issue
Fixed terminal typeahead issues
Fixed HttpProfile editing issue
Fixed POST /api/users API endpoint authentication issue
Fixed profiles using Cookie header
Fixed profile using curly brace character
Fix create/edit for ReferenceSourceLibraries,ReferenceAssemblies,EmbeddedResources
Fix launcher commands (i.e. BypassUacGrunt, WMIGrunt, PowerShellRemotingGrunt)
Fix Launcher properties not being applied during generation
Fixed Graph with BridgeListener issue