Bypassing Blockchain Authorization via Unsecured Functions
Note: Since the first part of this series I have also uploaded some further videos on remediation of reentrancy and dealing with compiler versions when working with this hacking blockchain series.Head to the console cowboys YouTube account to check those out.Haha as mentioned before I always forget to post blogs when I get excited making videos and just move on to my next project… So make sure to subscribe to the YouTube if you are waiting for any continuation of a video series.. It may show up there way before here.
Note 2: You WILL run into issues when dealing with Ethereum hacking, and you will have to google them as versions and functionality changes often... Be cognizant of versions used hopefully you will not run into to many hard to fix issues.
In the second part of this lab series we are going to take a look at privacy issues on the blockchain which can result in a vulnerably a traditional system maynot face. Since typically blockchain projects are open source and also sometimes viewable within blockchain explorers but traditional application business logic is not usually available to us. With traditional applications we might not find these issues due to lack of knowledge of internal functionality or inability to read private values on a remote server side script.After we review some issues we are going to exploit an authorization issues by writing web3.js code to directly bypass vertical authorization restrictions.
Blockchain projects are usually open source projects which allow you to browse their code and see what's going on under the hood.This is fantastic for a lot of reasons but a developer can run into trouble with this if bad business logic decisions are deployed to the immutable blockchain.In the first part of this series I mentioned that all uploaded code on the blockchain is immutable. Meaning that if you find a vulnerability it cannot be patched. So let's think about things that can go wrong..
A few things that can go wrong:
Randomization functions that use values we can predict if we know the algorithm
Hard-coded values such as passwords and private variables you can't change.
Publicly called functions which offer hidden functionality
Race conditions based on how requirements are calculated
Since this will be rather technical, require some setup and a lot of moving parts we will follow this blog via the video series below posting videos for relevant sections with a brief description of each.I posted these a little bit ago but have not gotten a chance to post the blog associated with it.Also note this series is turning into a full lab based blockchain exploitation course so keep a lookout for that.
In this first video you will see how data about your project is readily available on the blockchain in multiple formats for example:
ABI data that allows you to interact with methods.
Actual application code.
Byte code and assembly code.
Contract addresses and other data.
Lab Video Part 1: Blockchain OSINT:
Once you have the data you need to interact with a contract on the blockchain via some OSINT how do you actually interface with it? That's the question we are going to answer in this second video. We will take the ABI contract array and use it to interact with methods on the blockchain via Web3.js and then show how this correlates to its usage in an HTML file
Lab Video Part 2: Connecting to a Smart Contract:
Time to Exploit an Application:
Exploit lab time, I created an vulnerable application you can use to follow along in the next video. Lab files can be downloaded from the same location as the last blog located below. Grab the AuthorizationLab.zip file:
Ok so you can see what's running on the blockchain, you can connect to it, now what?Now we need to find a vulnerability and show how to exploit it. Since we are talking about privacy in this blog and using it to bypass issues. Lets take a look at a simple authorization bypass we can exploit by viewing an authorization coding error and taking advantage of it to bypass restrictions set in the Smart Contract.You will also learn how to setup a local blockchain for testing purposes and you can download a hackable application to follow along with the exercises in the video..
Lab Video Part 3: Finding and hacking a Smart Contract Authorization Issue:
Summary:
In this part of the series you learned a lot, you learned how to transfer your OSINT skills to the blockchain. Leverage the information found to connect to that Smart Contract. You also learned how to interact with methods and search for issues that you can exploit. Finally you used your browsers developer console as a means to attack the blockchain application for privilege escalation.
NanoCore is one of the most powerful RATs ever created. It is capable of taking complete control of a victim's machine. It allows a user to control the system with a Graphical User Interface (GUI). It has many features which allow a user to access remote computer as an administrator. Download nanocore rat 1.2.2.0 cracked version free of cost.
NanoCore's developer was arrested by FBI and pleaded guilty in 2017 for developing such a malicious privacy threat, and sentenced 33 months in prison.
FEATURES
Complete Stealth Remote Control
Recover Passwords from the Victim Device
Manage Networks
Manage Files
Surveillance
Plugins (To take it to the next level)
Many advanced features like SCRIPTING
DOWNLOAD NANOCORE RAT 1.2.2.0 CRACKED – REMOTE ADMINISTRATION TOOL
This Video is absolutely for Educational Purposes only, please don't do any illegal activity. If you do then I'm not responsible for your illegal activity. The purpose of this video is to show you How hackers can hack your social media by using their own local servers.
Basically these type of attacks known as Social Engineering attacks or Phishing. Attacker just send the duplicate vulnerable HTML page to the victim, when victim enters any type of information to that vulnerable page it'll automatically received by the attacker.
Phishing is a form of fraud in which an attacker masquerades as a reputable entity or person in email or other communication channels. The attacker uses phishing emails to distribute malicious links or attachments that can perform a variety of functions, including the extraction of login credentials or account information from victims.
How phishing works
Phishing attacks typically rely on social networking techniques applied to email or other electronic communication methods, including direct messages sent over social networks, SMS text messages and other instant messaging modes.
Phishers may use social engineering and other public sources of information, including social networks like LinkedIn, Facebook and Twitter, to gather background information about the victim's personal and work history, his interests, and his activities.
Hacking by PHP
As PHP is server side scripting language so first of all you have need to install a local server (WAMP, XAMPP or LAMPP) over your system. Because if there is no any server running on your system then you can't even run your PHP script. So if you wanna do a programming with PHP this is the first step to download and install a server from the Internet. You can easily download and install servers by watching my videos. Just visit my YouTube channel and watch there.
Hacking Facebook By Using PHP Script | Social Engineering Attack | You can perform this attack over LAN and WAN (Same or Different Networks)
There are many basic shellcodes that can be emulated from the beginning from the end providing IOC like where is connecting and so on. But what can we do when the emulation get stuck at some point?
The console has many tools to interact with the emulator like it was a debugger but the shellcode really is not being executed so is safer than a debugger.
In some shellcodes the emulator emulates millions of instructions without problem, but in this case at instruction number 176 there is a crash, the [esp + 30h] contain an unexpected 0xffffffff.
There are two ways to trace the memory, tracing all memory operations with -m or inspecting specific place with -i which allow to use registers to express the memory location:
Eax is not a counter, is getting hardcoded values which is probably an API name:
In this case this shellcode depend on previous states and crash also in the debugger because of register values. this is just an example of how to operate in cases where is not fully emulated.
In next chapter will see how to unpack and dump to disk using the emulator.