Adding New Agent Commands

The SkoveNet C2 agent features a modular command execution system. New commands can be added easily by implementing the Command interface and registering them with the agent's Executor. This allows you to add specific built-in functionality (e.g., upload, download, screenshot) without cluttering the existing code.

1. Implement the Command Interface

To add a new command, create a new file in pkg/command/ (e.g., pkg/command/download.go) and define a struct that implements the Command interface:

package command

import (
    "context"
    "fmt"
)

type DownloadCommand struct{}

func NewDownloadCommand() *DownloadCommand {
    return &DownloadCommand{}
}

// Name returns the trigger word for this command.
// When the controller sends a command starting with this word, this struct handles it.
func (c *DownloadCommand) Name() string {
    return "download"
}

// Description provides a brief summary of what the command does.
func (c *DownloadCommand) Description() string {
    return "Downloads a file from the C2 server"
}

// Execute performs the command logic.
// It receives the context and the raw arguments string (everything after the command name).
// It is up to the command to parse `rawArgs` contextually (e.g., split by space, parse paths).
func (c *DownloadCommand) Execute(ctx context.Context, rawArgs string) (string, error) {
    if rawArgs == "" {
        return "", fmt.Errorf("missing file path")
    }

    // ... logic to read/download the file ...

    return fmt.Sprintf("Successfully downloaded %s", rawArgs), nil
}

2. Register the Command

Once you have implemented your command struct, register it with the executor when the Handler is created.

Open pkg/command/handler.go and locate the NewHandler function. Add your newly created command using executor.Register():

func NewHandler(n *node.Node) *Handler {
    executor := NewExecutor()

    // Register custom commands here
    executor.Register(NewDownloadCommand())
    // executor.Register(NewUploadCommand())

    return &Handler{
        node:     n,
        executor: executor,
    }
}