b3acon: In-Memory C# IMAP C2 over Email

b3acon is a mail based C2 that uses an in-memory, dynamically compiled C# IMAP client via PowerShell. It communicates entirely through standard email protocols, fetching commands from email drafts and sending execution results to the inbox.

Features

• Command and Control via Email
• In-memory dynamic C# compilation
• Reads commands from email drafts
• Sends output back to inbox via SMTP
• Works with Yandex (other IMAP/SMTP providers may work with small adjustments)
• Includes a Web Generator that outputs in:
  • PowerShell
  • HTA
  • VBS
  • JavaScript (WScript)
• Optional Base64 encoding for PowerShell
• Supports both fixed and randomized delay options

How It Works

1. You (the operator) create a draft email:

   • The Subject is the command ID — a number between 0 and 9999 (e.g., 101)
   • The Body contains the actual PowerShell command:

     Get-Process
     

2. The script runs on the target system and:

   • Connects to IMAP and reads the Drafts folder
   • Skips any draft IDs that have already been executed
   • Executes new commands found in draft bodies
   • Sends the result back to the same inbox via SMTP

3. Output delivery:

   • If the command produces output (e.g., Get-Process), it will appear in the Inbox as an email with subject:

     Output of command ID 101
     
   • If the command generates no output (e.g., Start-Process calc.exe), the email will still be sent with a message confirming successful execution.

4. To issue new commands:

   • Create a new draft or modify an existing one with a new numeric subject (e.g., 102, 103, etc.)
   • Already-executed IDs will be skipped unless the script is restarted

HTML Script Generator

The project includes a self-contained HTML file that lets you generate scripts via browser.

• Configuration for:
  • IMAP/SMTP servers
  • Username, password, ports
  • Fixed delay (in seconds)
  • Optional randomized delay (e.g., 30–90 seconds)
• Output options:
  • PowerShell (raw, editable, copy-paste)
  • HTA
  • VBS
  • JS (for WScript)
• Optional:
  • Base64-encoded PowerShell payload
  • Auto-embed in HTA/VBS/JS wrappers

Supported Output Types

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