Harnsweep - EVM Asset Recovery Tool
Complete User Manual
Table of Contents
- Introduction
- How It Works
- Features Overview
- Feature 1: Token Sweep
- Feature 2: Custom Call
- Feature 3: Full Rescue
- Feature 4: Revoke Auth
- Fee Structure
- Troubleshooting
- Security Considerations
Introduction
Harnsweep is a tool designed to recover assets from compromised EVM wallets. Using EIP-7702 technology, it enables atomic transaction execution where all operations occur in a single transaction, preventing hackers from intercepting the rescue process.
When to Use Harnsweep
- Your wallet private key has been leaked or compromised
- Your wallet has been targeted by a drainer or scam
- You need to claim an airdrop from a compromised wallet
- You want to evacuate all assets before hackers can access them
Prerequisites
- Private Key of the Compromised Wallet - The wallet containing assets to be rescued
- Private Key of a Sponsor Wallet - A separate wallet with ETH to pay for gas fees
- Token Contract Addresses - The contract addresses of tokens to be rescued (if applicable)
How It Works
EIP-7702 Technology
EIP-7702 enables delegated execution where:
- Wallet A (compromised) signs an authorization to a smart contract
- Wallet B (sponsor) sends a transaction that executes code on behalf of Wallet A
- All operations occur in a single atomic transaction
- Hackers cannot intercept because there are no separate transactions to front-run
Rescue Flow
Features Overview
| Feature | Description | Use Case |
|---|---|---|
| Token Sweep | Transfer ERC-20 tokens | Rescue tokens from compromised wallet |
| Custom Call | Execute custom function + sweep | Claim airdrop then sweep tokens |
| Full Rescue | Custom call + token + ETH sweep | Evacuate all assets at once |
| Revoke Auth | Cancel delegation | Return wallet to normal state |
Feature 1: Token Sweep
Description
Transfers ERC-20 tokens from the compromised wallet to the sponsor wallet.
When to Use
- Your wallet contains tokens you want to rescue
- No claiming is required, only transferring existing tokens
Steps
- Select Rescue Type: Token Sweep
- Enter Compromised Identity (PK):
- Enter Sponsor Identity (PK):
- Enter Token Addresses:
Separate multiple tokens with commas. - Click Execute
Result
- Tokens are transferred to sponsor wallet
- 25% fee deducted to provider
- 75% sent to sponsor
Example
Feature 2: Custom Call
Description
Executes a custom transaction (such as claiming an airdrop) then sweeps the resulting tokens.
When to Use
- There is an unclaimed airdrop in the compromised wallet
- You need to call a specific function on a smart contract
- Tokens are not yet in the wallet and need to be claimed first
Steps
- Select Rescue Type: Custom Call
- Enter Private Keys (same as Token Sweep)
- Enter Target Contract Address:
-
Enter Custom Transaction Data (Hex):
How to obtain Hex Data:
- Open the contract on Basescan, go to Write Contract
- Connect wallet (do not confirm the transaction)
- View the hex data in the wallet popup
- Copy the hex data
- Enter Token Addresses:
- Click Execute
Result
- Function is called (airdrop claimed)
- Resulting tokens are immediately swept to sponsor
- All in one atomic transaction
Common Hex Data Examples
| Function | Hex Data |
|---|---|
| claim() | 0x4e71d92d |
| claimTokens() | varies by contract |
| harvest() | varies by contract |
Feature 3: Full Rescue
Description
The most comprehensive mode: Custom Call + Token Sweep + Native ETH Sweep.
When to Use
- You want to evacuate ALL assets from a compromised wallet
- There is an airdrop + tokens + remaining ETH to rescue
- Emergency situation requiring speed
Steps
- Select Rescue Type: Full Rescue
- Enter Private Keys
- Enter Target Contract Address:
- Enter Custom Transaction Data (Hex):
- Enter Token Addresses:
- Click Execute
Result
In one transaction:
- Custom function is executed (airdrop claimed)
- All specified tokens are swept
- All remaining ETH is swept
- 25% fee is deducted from each asset type
Example
Feature 4: Revoke Auth
Description
Cancels the EIP-7702 delegation from the wallet, returning it to its normal state.
When to Use
- After rescue is complete, to clean up the wallet
- You do not want the wallet to remain delegated to the contract
- Additional security measure
Steps
- Select Rescue Type: Revoke Auth
- Enter Private Keys
- Compromised: wallet whose delegation you want to revoke
- Sponsor: wallet to pay for gas
- Click Execute
Result
- Delegation is revoked (delegated to address 0x0)
- Wallet returns to normal state
- FREE - no fee charged for revoke
Note
Revoke is a security operation and is not subject to the 25% fee.
Fee Structure
Standard Fee: 25%
| Operation | Fee |
|---|---|
| Token Sweep | 25% of tokens |
| Custom Call | 25% of resulting tokens |
| Full Rescue | 25% of all assets |
| Revoke Auth | FREE |
Fee Distribution
- 75% goes to Sponsor Wallet (user)
- 25% goes to Provider Wallet
Calculation Example
Troubleshooting
Error: Transaction Failed
Possible Causes:
- Insufficient gas in sponsor wallet
- No tokens in compromised wallet
- Incorrect contract address
Solutions:
- Ensure sponsor has ETH for gas (minimum 0.001 ETH)
- Check token balance in compromised wallet using block explorer
- Verify contract address on block explorer
Error: Invalid Chain ID
Possible Causes:
- Network not supported
- Backend configuration issue
Solutions:
- Ensure correct network is selected (Base)
- Verify contract is deployed on the selected network
Error: Authorization Failed
Possible Causes:
- Invalid private key
- Nonce mismatch
Solutions:
- Ensure private key is complete (starts with 0x)
- Wait a few seconds and try again
Transaction Successful but Tokens Did Not Transfer
Possible Causes:
- Token balance is 0
- Incorrect token address
Solutions:
- Check token balance on block explorer
- Verify token contract address
Security Considerations
Important
- Private Keys are Confidential
- Never share your private key with anyone
- Harnsweep processes private keys client-side and does NOT store them
- Use a Separate Sponsor Wallet
- Do not use your main wallet as the sponsor
- Create a dedicated wallet for rescue operations
- Verify Transactions
- Always check transactions on block explorer
- Confirm assets have been transferred
- Revoke After Rescue
- Use the Revoke Auth feature after completing rescue
- This removes delegation from the wallet
Data Processing
| Data | Sent to Server | Stored |
|---|---|---|
| Private Key | Yes (for tx signing) | NO |
| Transaction Data | Yes | Temporary logs |
| IP Address | Yes | Rate limiting only |
Harnsweep - Secure. Atomic. Private.
Last Updated: April 2026