Posted on

Blogpost: Ethereum Threat Actors Part 3 — Phishings/Scams using Smart Contracts

Ethereum smart contract malware threat actor phishing patrick ventuzelo blogpost quoscient analysis scams

2019/04/03 @ QuoScient Medium

In part three of our mini-series (see part #1 & part #2) describing how cybercrime actors are using the Ethereum blockchain for fraudulent means, we analyze a phishing tactic that used a smart contract address. Interestingly, this smart contract is not unique and the exact same closed-source bytecode is used in more than 130 thousand smart contracts.

  1. Phishing on Forums/Telegram.
  2. Quick analysis of the Smart contract Bytecode
  3. Who is behind 0xAf1931c20ee0c11BEA17A41BfBbAd299B2763bc0?
  4. Similar Luno user wallets Used for Phishing
  5. Conclusion
  6. Indicator of Compromise

link / pdf

Posted on

Talk @ EthCC 2019: Let’s dig inside Ethereum Smart Contracts compiled to WebAssembly

Ethereum ETHCC Paris reverse webassembly patrick ventuzelo analysis smart contract Parity Kovan mainnet testnet conference talk

2019/02/18 @ EthCC 2019

At Devcon4, Vitalik annonced that WebAssembly (wasm) will be part of Ethereum 2.0 (Serenity). It’s already possible to compile smart contracts to wasm modules and run them in the Kovan network.

Using WebAssembly smart contract doesn’t mean using secure smart contract.

In this talk, I will explain what’s inside a WebAssembly module and illustrate how to analyze wasm Ethereum smart contracts to find vulnerabilities and unoptimization.

  1. Introduction
  2. WebAssembly basics
  3. Program analysis
  4. Parity Helloworld
  5. WASM module Vulnerabilities
  6. Conclusion

link / slides / video

Posted on

Workshop @ Geneva Annual Blockchain Congress 2019: Introduction to Ethereum smart contract development and security

blockchain geneva octopus patrick ventuzelo ethereum eth introduction security smart contract workshop

2019/01/21 @ Geneva Annual Blockchain Congress 2019

Ethereum is one of the top5 cryptocurrency on the market cap and the major public smart contract platform. This position is due partially to the possibility to create decentralized applications (Dapps) by writing smart contracts. The Solidity source code can contains flaws (reentrancy, integer overflow/underflow, bad randomness, backdoor, …) and it’s important to keep security in mind when developing smart contracts.

After this workshop delivered by Quoscient, attendees will be able to create simple Ethereum smart contract, upload and interact with them on the blockchain.
We will also discuss about major security flaws/vulnerabilities that have occurred on the Ethereum main-net and how to prevent them from a developer point of view.

The following points will be covered in the workshop:

  1. Introduction of Ethereum
  2. Smart contracts development
  3. Vulnerabilities inside smart contracts
  4. Going deeper & Questions

slides

Posted on

Workshop @ BlackAlps 2018: Reversing and Vulnerability research of Ethereum Smart Contracts

blackalps 2018 ethereum reverse vulnerability research octopus patrick ventuzelo smart contract evm ethereum ETH EVM workshop

2018/11/08 @ BlackAlps 2018

Ethereum is the reference of smart contract platform due to the possibility to create decentralized applications (Dapps) by writing smart contracts. The Solidity source code of those smart contracts are not always available and can contains flaws (reentrancy, integer overflow/underflow, bad randomness, backdoor, ….). Some smart contract handle thousand of ETH and can’t be modified once pushed into the blockchain. More than 90% of them doesn’t provide the associated Solidity source code and that’s also why be able to reverse and analyze Ethereum smart contract (only with the EVM bytecode) make even more sense.

This workshop is intended to bring attendees the basic skills (theoretical and practical) to analyze Ethereum smart contracts. After the workshop, they will be able to reverse, debug and find basic vulnerabilities into real-life smart contracts without having the Solidity source code.

The following points will be covered in the workshop:

  1. Quick introduction of Ethereum
  2. Basic Ethereum testing lab
  3. Reverse engineering of Ethereum smart contracts
  4. Analysis and vulnerability research
  5. Going deeper & Questions

link / slides / video

Posted on

Talk @ Devcon 4 – 2018: Reversing Ethereum Smart Contracts to find out what’s behind EVM bytecode

devcon iv ethereum patrick ventuzelo reverse evm octopus cfg analysis smart contract vulnerability research ocptimization talk

2018/11/01 @ Devcon iv.

Reverse engineering is a common technique used by security researcher to understand and analyze the behavior of closed-source binaries.

If you apply this to Ethereum smart contract (and more specifically on the EVM bytecode), thats allow you to analyze and verify the result of your Solidity source code compilation. 

From a developer point of view, it can save you a lot of time and money if you succeed to detect flaws and missing bytecode optimization.

Also, providing the Solidity source code it’s not mandatory during the smart contract creation, that’s why being able to directly reverse the EVM bytecode make even more sense if you want to understand the behavior of external smart contracts.

slides / video

Posted on

Workshop @ hack.lu 2018: Reversing and Vulnerability research of Ethereum Smart Contracts

hacklu 2018 ethereum reverse vulnerability octopus patrick ventuzelo smart contract evm ethereum ETH

2018/10/18 @ hack.lu 2018

This workshop is intended to bring attendees the basic skills (theoretical and practical) to analyze Ethereum smart contracts. After the workshop, they will be able to reverse, debug and find basic vulnerabilities into real-life smart contracts without having the Solidity source code.

The following points will be covered in the workshop:

  1. Quick introduction of Ethereum
  2. Basic Ethereum testing lab
  3. Reverse engineering of Ethereum smart contracts
  4. Analysis and vulnerability research
  5. Going deeper & Questions

link / slides

Posted on

Talk @ Recon MTL 2018: Reverse Engineering Of Blockchain Smart Contracts

recon montreal reverse ethereum blockchain smart contract neo eos webassembly patrick ventuzelo

RECON Montreal 2018

Many platforms using blockchain technology have emerged in 2017 and take the top 10 position of the cryptocurrencies’s MarketCap. One of the main reasons behind is the possibility to create decentralized applications (dapps) by writing Smart Contracts.

During this presentation, we will analyze the implementation of smart contract mechanism (Virtual Machine, assembly language, instructions sets, …) used by those platforms. We will analyze the assembly languages and instructions sets used by the Virtual Machine of the major blockchain platforms.

We will see how to disassemble and reconstruct the CFG (Control Flow Graph) of those smart contracts and the tools actually available to perform a deeper security analysis.

This talk aims at covering the following platforms:

link / slides / video (not yet)