In this article, I will be talking about how you can develop a extension for the popular Web Application Security tool Burp Suite. A Burp Suite extension is a custom plugin for the Burp Suite web security testing platform. Burp Suite is a popular tool used by security professionals to test the security of web applications and APIs. Extensions allow users to extend the functionality of Burp Suite by adding new features and capabilities. For example, an extension might add a new tab to the Burp Suite user interface, or it might add a new type of scan or attack to the platform. Extensions are typically written in the Java programming language, and they can be loaded and managed using the Burp Suite Extender tool.
To write a Burp Suite extension, you will first need to have a basic understanding of the Java programming language. Once you have that, you can start by following these steps:
After your extension is loaded, you can use the Burp Suite Extender to manage it and view any output or error messages it generates. You can also use the other tools in Burp Suite, such as the Proxy and Repeater, to test your extension and see how it performs in a real-world scenario.
Here are some examples of code for developing Burp Suite extensions:
To get started with developing Burp Suite extensions, you will need to have a basic understanding of the programming language you plan to use, as well as a good understanding of web application security and the Burp Suite Extender API. You may also find it helpful to refer to the documentation and examples provided by the Burp Suite team, as well as any other resources and tutorials available online.
Java :
Here is an example of a simple Burp Suite extension written in Java that logs all requests and responses to the Burp Suite console:
import burp.*;
public class Logger implements IHttpListener {
private IBurpExtenderCallbacks callbacks;
private IExtensionHelpers helpers;
public Logger(IBurpExtenderCallbacks callbacks) {
this.callbacks = callbacks;
this.helpers = callbacks.getHelpers();
}
@Override
public void processHttpMessage(int toolFlag, boolean messageIsRequest, IHttpRequestResponse messageInfo) {
if (messageIsRequest) {
// Log the request to the console
callbacks.printOutput(helpers.bytesToString(messageInfo.getRequest()));
} else {
// Log the response to the console
callbacks.printOutput(helpers.bytesToString(messageInfo.getResponse()));
}
}
}
This extension implements the IHttpListener interface and overrides the processHttpMessage method, which is called whenever a request or response is processed by Burp Suite. The extension logs the request or response to the Burp Suite console using the callbacks.printOutput method.
Here is an example of a Burp Suite extension written in Java that logs all requests and responses to a file:
import burp.*;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
public class FileLogger implements IHttpListener {
private IBurpExtenderCallbacks callbacks;
private IExtensionHelpers helpers;
private File logFile;
public FileLogger(IBurpExtenderCallbacks callbacks) {
this.callbacks = callbacks;
this.helpers = callbacks.getHelpers();
this.logFile = new File(“log.txt”);
}
@Override
public void processHttpMessage(int toolFlag, boolean messageIsRequest, IHttpRequestResponse messageInfo) {
if (messageIsRequest) {
// Log the request to the file
try {
Files.write(Paths.get(logFile.getAbsolutePath()), messageInfo.getRequest());
} catch (IOException e) {
e.printStackTrace();
}
} else {
// Log the response to the file
try {
Files.write(Paths.get(logFile.getAbsolutePath()), messageInfo.getResponse());
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
This extension implements the IHttpListener interface and overrides the processHttpMessage method, which is called whenever a request or response is processed by Burp Suite. The extension logs the request or response to a file using the Files.write method from the Java NIO library.
To use this extension, you will need to compile it to a .class file using a Java compiler and load it into Burp Suite using the Extender tab.
Here is an example of a Burp Suite extension written in Java that adds a custom tab to the Burp Suite UI:
import burp.*;
import javax.swing.*;
import java.awt.*;
public class CustomTab implements ITab {
private JPanel panel;
public CustomTab(IBurpExtenderCallbacks callbacks) {
// Set up the panel
this.panel = new JPanel();
this.panel.setLayout(new BorderLayout());
// Add a label to the panel
JLabel label = new JLabel(“Hello, World!”);
this.panel.add(label, BorderLayout.CENTER);
}
@Override
public String getTabCaption() {
return “Custom Tab”;
}
@Override
public Component getUiComponent() {
return this.panel;
}
}
This extension implements the ITab interface and overrides the getTabCaption and getUiComponent methods. The getTabCaption method returns the caption that will appear on the tab in the Burp Suite UI, and the getUiComponent method returns the panel that will be displayed in the tab.
To use this extension, you will need to compile it to a .class file using a Java compiler and load it into Burp Suite using the Extender tab.
Here is an example of a Burp Suite extension written in Java that adds a custom column to the HTTP History tab:
import burp.*;
import java.util.ArrayList;
import java.util.List;
public class CustomColumn implements ITableItemInsertionListener {
private IBurpExtenderCallbacks callbacks;
private IExtensionHelpers helpers;
public CustomColumn(IBurpExtenderCallbacks callbacks) {
this.callbacks = callbacks;
this.helpers = callbacks.getHelpers();
// Register the extension as a table item insertion listener
callbacks.registerTableItemInsertionListener(this);
}
@Override
public void newTableItem(ITableItem item) {
// Add a custom column to the HTTP History tab
List<String> customColumn = new ArrayList<>();
customColumn.add(“Custom Column”);
item.addRow(customColumn);
}
}
This extension implements the ITableItemInsertionListener interface and overrides the newTableItem method, which is called whenever a new item is added to the table in the HTTP History tab. The extension adds a custom column to the item using the addRow method.
To use this extension, you will need to compile it to a .class file using a Java compiler and load it into Burp Suite using the Extender tab.
Python :
Here is an example of a simple Burp Suite extension written in Python that logs all requests and responses to the Burp Suite console:
from burp import IBurpExtender
from burp import IHttpListener
class BurpExtender(IBurpExtender, IHttpListener):
def registerExtenderCallbacks(self, callbacks):
# Set up extension
self.callbacks = callbacks
self.helpers = callbacks.getHelpers()
# Register extension as an HTTP listener
callbacks.registerHttpListener(self)
def processHttpMessage(self, toolFlag, messageIsRequest, messageInfo):
if messageIsRequest:
# Log the request to the console
self.callbacks.printOutput(self.helpers.bytesToString(messageInfo.getRequest()))
else:
# Log the response to the console
self.callbacks.printOutput(self.helpers.bytesToString(messageInfo.getResponse()))
This extension implements the IBurpExtender and IHttpListener interfaces and overrides the processHttpMessage method, which is called whenever a request or response is processed by Burp Suite. The extension logs the request or response to the Burp Suite console using the callbacks.printOutput method.
To use this extension, you will need to save it to a file with a .py extension and load it into Burp Suite using the Extender tab.
Here is an example of a Burp Suite extension written in Python that sends all requests and responses to a Slack channel:
from burp import IBurpExtender
from burp import IHttpListener
import requests
SLACK_WEBHOOK_URL = “https://hooks.slack.com/services/YOUR/WEBHOOK/URL”
class BurpExtender(IBurpExtender, IHttpListener):
def registerExtenderCallbacks(self, callbacks):
# Set up extension
self.callbacks = callbacks
self.helpers = callbacks.getHelpers()
# Register extension as an HTTP listener
callbacks.registerHttpListener(self)
def processHttpMessage(self, toolFlag, messageIsRequest, messageInfo):
if messageIsRequest:
# Send the request to Slack
request = self.helpers.bytesToString(messageInfo.getRequest())
self.sendToSlack(request)
else:
# Send the response to Slack
response = self.helpers.bytesToString(messageInfo.getResponse())
self.sendToSlack(response)
def sendToSlack(self, message):
# Send a message to a Slack channel using a webhook
payload = {
“text”: message
}
requests.post(SLACK_WEBHOOK_URL, json=payload)
This extension implements the IBurpExtender and IHttpListener interfaces and overrides the processHttpMessage method, which is called whenever a request or response is processed by Burp Suite. The extension sends the request or response to a Slack channel using a webhook and the requests library.
To use this extension, you will need to install the requests library and save the extension to a file with a .py extension. You can then load it into Burp Suite using the Extender tab. You will also need to replace the SLACK_WEBHOOK_URL variable with the URL of your Slack webhook.
Here is an example of a Burp Suite extension written in Python that adds a custom menu item to the Burp Suite context menu:
from burp import IBurpExtender
from burp import IContextMenuFactory
class BurpExtender(IBurpExtender, IContextMenuFactory):
def registerExtenderCallbacks(self, callbacks):
# Set up extension
self.callbacks = callbacks
self.helpers = callbacks.getHelpers()
# Register extension as a context menu factory
callbacks.registerContextMenuFactory(self)
def createMenuItems(self, invocation):
# Create a menu item that will be displayed in the context menu
menuItem = JMenuItem(“Custom Menu Item”)
# Define the action that will be taken when the menu item is clicked
def actionPerformed(event):
# Get the selected message
request = invocation.getSelectedMessages()[0]
print(request)
# Add the action listener to the menu item
menuItem.addActionListener(actionPerformed)
# Return the menu item
return [menuItem]
This extension implements the IContextMenuFactory interface and overrides the createMenuItems method. The createMenuItems method returns a list of menu items that will be displayed in the context menu when the user right-clicks on a request or response in Burp Suite. The extension defines an action listener that will be triggered when the menu item is clicked, which in this case prints the selected message to the console.
To use this extension, you will need to save it to a file with a .py extension and load it into Burp Suite using the Extender tab.
JavaScript :
Here is an example of a simple Burp Suite extension written in JavaScript that logs all requests and responses to the Burp Suite console:
importClass(org.parosproxy.paros.extension.ExtensionAdaptor);
importClass(org.parosproxy.paros.network.HttpMessage);
var extension = new ExtensionAdaptor() {
processHttpMessage: function(toolFlag, messageIsRequest, messageInfo) {
if (messageIsRequest) {
// Log the request to the console
console.log(messageInfo.getRequest());
} else {
// Log the response to the console
console.log(messageInfo.getResponse());
}
}
};
This extension overrides the processHttpMessage method, which is called whenever a request or response is processed by Burp Suite. The extension logs the request or response to the Burp Suite console using the console.log method.
To use this extension, you will need to save it to a file with a .js extension and load it into Burp Suite using the Extender tab.
Here is an example of a Burp Suite extension written in JavaScript that sends all requests and responses to a Discord channel:
importClass(org.parosproxy.paros.extension.ExtensionAdaptor);
importClass(org.parosproxy.paros.network.HttpMessage);
var Discord = Java.type(“com.google.gson.Gson”);
var HttpURLConnection = Java.type(“java.net.HttpURLConnection”);
var URL = Java.type(“java.net.URL”);
var DISCORD_WEBHOOK_URL = “https://discordapp.com/api/webhooks/YOUR/WEBHOOK/URL”;
var extension = new ExtensionAdaptor() {
processHttpMessage: function(toolFlag, messageIsRequest, messageInfo) {
if (messageIsRequest) {
// Send the request to Discord
var request = messageInfo.getRequest();
this.sendToDiscord(request);
} else {
// Send the response to Discord
var response = messageInfo.getResponse();
this.sendToDiscord(response);
}
},
sendToDiscord: function(message) {
// Send a message to a Discord channel using a webhook
var connection = new URL(DISCORD_WEBHOOK_URL).openConnection();
connection.setDoOutput(true);
connection.setRequestMethod(“POST”);
connection.setRequestProperty(“Content-Type”, “application/json”);
var payload = {
“content”: message
};
connection.getOutputStream().write(new Discord().toJson(payload).getBytes(“UTF-8”));
connection.getInputStream().read();
}
};
This extension overrides the processHttpMessage method, which is called whenever a request or response is processed by Burp Suite. The extension sends the request or response to a Discord channel using a webhook and the HttpURLConnection and Gson classes from the Java API.
To use this extension, you will need to save it to a file with a .js extension and load it into Burp Suite using the Extender tab. You will also need to replace the DISCORD_WEBHOOK_URL variable with the URL of your Discord webhook.
Here is an example of a Burp Suite extension written in JavaScript that adds a custom button to the Burp Suite toolbar:
importClass(org.parosproxy.paros.extension.ExtensionAdaptor);
importClass(java.awt.event.ActionListener);
importClass(javax.swing.JButton);
var extension = new ExtensionAdaptor() {
// Initialize the extension
initExtension: function() {
// Create a button
var button = new JButton(“Custom Button”);
// Define the action that will be taken when the button is clicked
var actionPerformed = function(event) {
console.log(“Button clicked!”);
};
// Add the action listener to the button
button.addActionListener(new ActionListener(actionPerformed));
// Add the button to the toolbar
this.customizeUiComponent(button);
this.addToToolbar(button);
}
};
This extension overrides the initExtension method, which is called when the extension is loaded. The extension creates a button and defines an action listener that will be triggered when the button is clicked. The extension then adds the button to the Burp Suite toolbar using the customizeUiComponent and addToToolbar methods.
To use this extension, you will need to save it to a file with a .js extension and load it into Burp Suite using the Extender tab.
Here are a few book recommendations for learning about developing Burp Suite extensions:
There are a number of resources that can be helpful for developing Burp Suite extensions, including:
In this article, I tried to answer the question of how you can write an extension for Burp Suite. I hope the sample codes and additional resources were helpful. Take care and see you in my next post.
