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πŸ§™β€β™‚οΈ Loki Command & Control

Loki is a stage-1 command and control (C2) framework written in Node.js, built to script-jack vulnerable Electron apps MITRE ATT&CK T1218.015. Developed for red team operations, Loki enables evasion of security software and bypasses application controls by exploiting trusted, signed Electron apps.

Script-jacking hijacks the execution flow of an Electron app by modifying JavaScript files loaded in at runtime with arbitrary Node.js code. This technique can be leveraged to:

  • Backdoor the Electron app
  • Hollow out the Electron app
  • Chain execution to another process

While several tools already address leveraging script-jacking to chain execution to another process, Loki is the first to enable backdooring and hollowing of signed Electron apps without invalidating their code signing signature.

For more details on how Loki works, checkout this blog post:

πŸš€ Contributors

Name Contributions
Bobby Cooke Creator & Maintainer
Dylan Tran Creator
Ellis Springe Alpha Tester
Shawn Jones Assembly Execution Code
Simon Exley Video Creator
Clinton Elves Video Creator
John Hammond Video Creator

Videos

Check out this video by John Hammond on backdooring Cursor AI with Loki C2! 🎩

  • In the video he walks through discovering a new vulnerable Electron application, backdooring it with Loki C2, getting setup with the client GUI, and we even came up with two ways to keep the app running persistently in the background πŸͺ„ -- Cursor runs normally from the end users perspective! πŸ₯·

I Backdoored Cursor AI

Check out this video by Simon Exley & Clinton Elves on getting up and running with Loki C2! πŸ§™β€β™‚οΈ

Bypassing Windows Defender Application Control with Loki C2

Features & Details

  • Azure Storage Blob C2 channel
    • SAS Token to protect C2 storage account
  • AES encrypted C2 messages
  • Proxy-aware agent
    • Uses Chromium renderer child processes for agent, shellcode execution, and assembly fork-n-run style execution -- inherits proxy-aware capabilities of Chromium.
  • Teamserver-less
    • Unlike traditional C2's where agents send messages to a Teamserver, there is no Teamserver
    • The GUI client & agents both checkin to the same data-store
  • Hidden exection -- runs in the background

Commands

All agent commands are written in native Node.JS and do not require additional dependencies or library load events. With the exception of the scexec and assembly commands which do a library load on keytar.node and assembly.node

  • All commands accept paths using /, \ in paths will not work.
Command Description
help Display help. Usage: help or help scan
pwd Print working directory
ls File and directory listing
cat Display contents of a file
env Display process environment variables
spawn Spawn a child process
drives List drives
mv Move a file to a new destination
sleep Sleep for seconds with jitter
cp Copy a source file to a destination
exit-all Exits the agent, agent won't callback anymore
load Load a node PE file from disk into the process
scexec Execute shellcode
assembly Execute a .NET assembly and get command output
upload Upload a file from your local operator box to the remote agent box
download Download a file from remote agent box to local operator box
scan Perform TCP network scan across CIDR range with selected ports
dns DNS lookup. Leverages systems DNS configuration
set Set the Node load paths for assembly node and scexec nodes

Set - Loading Nodes from Application Control Exclusion Paths

  • If there are application control rules preventing library loads for the node files you can use the set command to change the load paths for assembly.node and scexec.node.
  • By using ls, cat, cp and mv you may be able to enumerate the application control rules to discover a writable directory that is an exclusion.
  • With this you can put the node files in the exclusion directory and use the set command to change their load path to the exclusion directory to bypass the application control.
  • For more details on this attack vector see the CRTO2 course by Daniel Duggan (@_RastaMouse)
[04-04-2025 8:50AM MST] advsim$ help set
Set the Node load paths for assembly node and scexec nodes
	set scexec_path C:/Users/user/AppData/ExcludedApp/scexec.node
	set assembly_path C:/Users/user/AppData/ExcludedApp/assembly.node
[04-04-2025 8:51AM MST] advsim$ set scexec_path C:/Users/user/AppData/ExcludedApp/scexec.node
SCEXEC Node Load Path Set to : C:/Users/user/AppData/ExcludedApp/scexec.node

Agent Features

For more information on Agent features click here

Client Features

For more information on Client features click here

πŸ§™β€β™‚οΈ Deploy Illusions

First you need to identify a vulnerable Electron application which does not do ASAR security integrity checks such as Microsoft Teams. Newer applications may have integrity checks preventing backdooring. Older versions of the target app are more likely to be vulnerable.

Vulnerable App Name EXE Name Version Discovery Credit
βœ… Microsoft Teams Teams.exe 1.7.00.13456 Andrew Kisliakov & mr.d0x
βœ… Cursor cursor.exe 0.48.7.0 John Hammond
βœ… VS Code code.exe chompie1337 & knavesec
βœ… Github Desktop GithubDesktop.exe 3.4.6.0 d_tranman & 0xBoku
βœ… Postman Postman.exe clod81
βœ… Obsidian Obsidian.exe clod81
βœ… Joplin Joplin.exe 0xAnom4ly
βœ… Discord Discord.exe clod81
βœ… Windsurf Windsurf.exe nero22k
βœ… Figma Figma.exe WaterBucket
βœ… RingCentral RingCentral.exe 4y45u45c4
βœ… ι˜Ώι‡ŒδΊ‘η›˜ aDrive 6.8.6 Adnnlnistrator
βœ… azuredatastudio azuredatastudio.exe 1.51.1 Adnnlnistrator
βœ… atom atom.exe 1.60.0 Adnnlnistrator
βœ… Bruno Bruno.exe 2.1.0 Tyler Schultz
βœ… KeeWeb KeeWeb.exe j0hnZ3RA
βœ… Wordpress Wordpress.com.exe j0hnZ3RA
βœ… Arduino IDE Arduino IDE.exe j0hnZ3RA
βœ… QRLWallet QRLWallet.exe 1.8.1 OnlySmrtSumX & tideboss
βœ… DevHub DevHub.exe 0.102.0 ab4y98
βœ… Asana Asana.exe 2.3.0 syro
βœ… Insomnia insomnia-11.0.2.exe 11.0.2 syro
❌ 1Password 1Password.exe
❌ Signal Signal.exe
❌ Slack slack.exe

Simple Instructions

You don't need to compile the agent when backdooring Electron apps. Just replace the contents of {ELECTRONAPP}/resources/app/ with the Loki agent files.

Detailed Instructions

Step 1 : Create Azure Storage Blob Account and get SAS Token

Step 2 : Create Obfuscated Loki Payload

  • Clone this repo and cd into it
  • Install Node.JS
  • Install javascript-obfuscator module
npm install --save-dev javascript-obfuscator
  • Run obfuscateAgent.js script to create a Loki payload with your Storage Account info
bobby$ node obfuscateAgent.js 
[+] Provide Azure storage account information:
        - Enter Storage Account  : 7f7584ty218ba5dba778.blob.core.windows.net
        - Enter SAS Token        : se=2025-05-28T23%3A14%3A48Z&sp=rwdlac&spr=https&sv=2022-11-02&ss=b&srt=sco&sig=5MXQzJ6FDZK8yYiBSgJ6FDZKgQzJMXBSgg6qE4ydrJ6FDZKSgg%3D

[+] Configuration:
        - Storage Account : 7f7584ty218ba5dba778.blob.core.windows.net
        - SAS Token       : se=2025-05-28T23%3A14%3A48Z&sp=rwdlac&spr=https&sv=2022-11-02&ss=b&srt=sco&sig=5MXQzJ6FDZK8yYiBSgJ6FDZKgQzJMXBSgg6qE4ydrJ6FDZKSgg%3D
        - Meta Container  : mllyi2zjmafjm

[+] Updated /Users/bobby/apr2/LokiC2/config.js with storage configuration. 
 - Enter into the Loki Client UI
        Loki Client > Configuration

[+] Modifying PE binaries to have new hashes...
        - Payload assembly.node hash : e9d126407264821d3c2d324da0e2d1bc13cbc53e7c56340fe12b07f69b707f02
        - Payload keytar.node   hash : 292c14ffebd6cae3df99d9fbee525e29a5a704f076b82207eb3e650de45b075d

[+] Payload ready!
         - Obfuscated payload in the ./app directory

Step 3 : Backdoor Electron Application

  • Your obfuscated Loki payload is output to ./app/
  • Change directory to the {ELECTRONAPP}/resources/
  • Delete everything
  • Copy the Loki ./app/ folder to {ELECTRONAPP}/resources/app/
  • Click the Electron PE file and make sure Loki works

Step 4 : Configure Loki Client

  • Launch the Loki GUI client

  • From the menubar click Loki Client > Configuration to open the Settings window

  • Enter in your Storage Account details and click Save

  • The agent should now render in the dashboard

  • Click the agent from the dashboard table to open the agent window

  • Test to ensure Loki works properly

Backdooring Electron Apps and Keeping the real Application Working as Normal

The most straightforward way to use Loki is to replace the files in {ELECTRONAPP}/resources/app/ with the Loki files. This hollows out the app, meaning the app won't function normally -- Loki replaced its functionality.

If you really want to keep the Electron application running and have it also deploy Loki in the background all hope is not lost! John Hammond and I figured out a way to keep the real Electron application running. We've added the file you will need to /loki/proxyapp/init.js in this repo.

It is currently setup to work for Cursor, discovered to be vulnerable by John Hammond.

For doing this you will need to:

  • Download the Cursor app
  • Paste all Loki files except package.json to cursor/resources/app/
    • Don't replace the real package.json
  • Copy /loki/proxyapp/init.js to cursor/resources/app/
  • Modify contents of cursor/resources/app/package.json to:
    • set "main":"init.js",
    • delete "type":"module",
    • delete "private":true,

How this works

  • With these changes Cursor.exe will load in init.js on click / execution
  • init.js reads in package.json
  • init.js changes "main":"init.js", -> "main":"main.js",
    • main.js is Loki
  • init.js spawns and disowns a new Cursor.exe which points to Loki
  • Loki is spawned in the background
  • init.js reads in package.json again
  • init.js changes "main":"main.js", -> "main":"./out/main.js",
    • ./out/main.js" is the real Cursor application
  • init.js spawns and disowns a new Cursor.exe which points to the real Cursor
  • Real Cursor app is spawned, visible and operates as normal
  • When Cursor is exited by the user:
    • init.js catches the exit
    • init.js reads in package.json for a third time
    • init.js changes "main":"./out/main.js", -> "main":"init.js",

This way the app is persistently backdoored and operates as normal. If the cursor app is exited loki will continue to run in the background.

Future

I'll make a script to automate this in the future.

Opsec Recommendations

Compilation Guides

These are the compile instructions for building the agents & clients. The instructions cover multiple platforms, including Windows, Linux, and macOS. It is recommended to compile the client on the target platform and architecture.

Client

Agents

If you are backdooring an Electron application then you don't need to compile agents.

I do not recommend compiling the agent and using it for operations. Agent compile instructions are for development.

Detection Guidance

  • Review the information provided by MITRE for more details, examples, and information about this TTP :
  • Execution of an electron app from a abnormal directory such as ~/Downloads/Teams/Teams.exe
  • Electron apps beaconing to an Azure Storage Blob *.blob.core.windows.net
  • SAS token usage in network traffic
  • Electron apps spawning child processes such as netstat.exe or whoami.exe
  • A directory with the name in the Loki package.json will be created in ~/AppData/Roaming/{NAME} when the Loki JavaScript executes in the Electron process.
  • This LOLBAS Teams entry covers detections for Electron application backdooring. The detection information has been copied below.
  • IOC: %LOCALAPPDATA%\Microsoft\Teams\current\app directory created
  • IOC: %LOCALAPPDATA%\Microsoft\Teams\current\app.asar file created/modified by non-Teams installer/updater
  • SIGMA rule to detect established Loki C2 from electron app
  • SIGMA rule to detect hijacking of Electron's app folder (Teams, VS Code, RingCentral, Postman) to load C2 framework

References || Acknowledgements || Offensive Electron Research

License

This project is licensed under the Business Source License 1.1. Non-commercial use is permitted under the terms of the license. Commercial use requires the author's explicit permission. On April 3, 2030, this license will convert to Apache 2.0. See LICENSE for full details.

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