Vulnerability research | Fuzzing | Reversing | WebAssembly | Ethereum
2020/03/03 @ EthCC 2020
In this talk, I briefly introduce WebAssembly concepts , Ewasm specificity and opcodes/instructions. Secondly, I show how to create Ewasm smart contract and expose different techniques/tools to perform WebAssembly module closed-source analysis. Finally, we go through some basic examples to apply reversing (reverse engineering) on those Ewasm contracts and understand the logic inside.
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.
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.
2019/02/18 @ QuoScient Medium
In part two of our mini-series (see part #1) describing how cybercrime actors are using the Ethereum blockchain for fraudulent means, we analyze a clipboard hijacker malware targeting Bitcoin and Ethereum users. This malware, renamed ClipboardWalletHijacker by Qihoo360 Security Center, was first discovered in June 2018, after having infected 300 thousand computers within a week.
2019/02/04 @ QuoScient Medium
As part of our research into how cybercrime actors using the Ethereum blockchain for fraudulent means, we analyzed a DotNet downloader that retrieves the malicious payload from URLs stored inside Ethereum transactions. We analyzed the sample provided by a German Security Researcher, Karsten Hahn @struppigel in this tweet.
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:
slides
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:
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.
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:
2018/09/15 @ ToorCon XX – 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.