A simple and easy EthersJS tool to send a bundle of transactions on L2s and fast paced EVM chains.
This tool was made to run on Arbitrum, but can work on other fast producing block chains. Because of the speed and the ability of posting transaction privately through the Arbitrum sequencer, one can send a bundle transaction to rescue a compromised wallet.
It is worth noting that on Arbitrum, JsonBatchRPC will post the transactions on adjacent blocks (N, N+1), whereas on other chains (Fantom for example), it'll put the transactions on the same block (Ref.).
If you wish to run the tool locally, you can install the dependencies with yarn and run it with ts-node
yarnA Dockerfile is also available to use the script inside of a docker container.
To run this project, you will need to add the following environment variables to your .env file. Template can be found in .env.example
If using something else than Arbitrum,
PROVIDER=https://arb1.arbitrum.io/rpc # Your provider URL
SEQUENCER=https://arb1-sequencer.arbitrum.io/rpc # Sequenecer URL if applicable. If not, use the same value as PROVIDER
VICTIM_WALLET_PK= # The compromised wallet private key
GAS_WALLET_PK= # The gas wallet private key
TARGET_CONTRACT=0x6e946816112526aA49b2F3F893677aac3328C7D7 # The target contract address
# The amount of ether to send from the gas wallet to the victim wallet
# In ether, e.g. 0.0001
ETHER_AMOUNT=0.0001
The default code TARGET_CONTRACT of the script is an Arbitrum Counter contract. Without any changes to the script, running it will send gas from the GAS_WALLET_PK to the VICTIM_WALLET_PK as a first Tx, followed by a call to the increment() function of the contract. This can be used for testing and to showcase how the script behave and the chain reacts.
To customize the calldata, one can update the following function
// ./rescue.ts
function buildCalldata() {
const iface = new ethers.Interface(['function setNumber(uint256 a)']);
const newNumber = 42;
const setNumberCall = iface.encodeFunctionData('setNumber', [newNumber]);
return [setNumberCall];
}To run the code locally
npx ts-node -T rescue.tsTo run the code using Docker
docker build --tag 'l2-frontrunning' . && docker run --rm 'l2-frontrunning'