Harnsweep - EVM Asset Recovery Tool

Complete User Manual


Table of Contents

  1. Introduction
  2. How It Works
  3. Features Overview
  4. Feature 1: Token Sweep
  5. Feature 2: Custom Call
  6. Feature 3: Full Rescue
  7. Feature 4: Revoke Auth
  8. Fee Structure
  9. Troubleshooting
  10. 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

  1. Private Key of the Compromised Wallet - The wallet containing assets to be rescued
  2. Private Key of a Sponsor Wallet - A separate wallet with ETH to pay for gas fees
  3. 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:

  1. Wallet A (compromised) signs an authorization to a smart contract
  2. Wallet B (sponsor) sends a transaction that executes code on behalf of Wallet A
  3. All operations occur in a single atomic transaction
  4. Hackers cannot intercept because there are no separate transactions to front-run

Rescue Flow

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[Victim Wallet] --> [Harnsweep API] --> [Blockchain]
(Compromised)        (Backend)           (Base/ETH)

1. Sign Authorization
2. Build Transaction
3. Broadcast to Network
4. Assets Transferred to Sponsor

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

  1. Select Rescue Type: Token Sweep
  2. Enter Compromised Identity (PK):
    0x... (private key of compromised wallet)
    
  3. Enter Sponsor Identity (PK):
    0x... (private key of sponsor wallet with ETH for gas)
    
  4. Enter Token Addresses:
    0xTokenAddress1, 0xTokenAddress2
    
    Separate multiple tokens with commas.
  5. Click Execute

Result

  • Tokens are transferred to sponsor wallet
  • 25% fee deducted to provider
  • 75% sent to sponsor

Example

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Token: 0x31C01Af9F467452A99260977E5E680b8AC6aE000
Balance: 1000 TRT

Result:
- Provider receives: 250 TRT (25%)
- Sponsor receives: 750 TRT (75%)

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

  1. Select Rescue Type: Custom Call
  2. Enter Private Keys (same as Token Sweep)
  3. Enter Target Contract Address:
    0x... (address of contract to call, e.g., Airdrop contract)
    
  4. Enter Custom Transaction Data (Hex):

    0x4e71d92d (example: hex for claim() function)
    

    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
  5. Enter Token Addresses:
    0x... (address of token to sweep after claiming)
    
  6. 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

  1. Select Rescue Type: Full Rescue
  2. Enter Private Keys
  3. Enter Target Contract Address:
    0x... (Airdrop/contract address for claiming)
    
  4. Enter Custom Transaction Data (Hex):
    0x... (hex data for claim function)
    
  5. Enter Token Addresses:
    0x... (tokens to sweep)
    
  6. 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

Compromised Wallet contains:
- Unclaimed airdrop: 100 TRT
- Token balance: 500 USDC
- ETH balance: 0.001 ETH

After Full Rescue:

Provider receives:
- 25 TRT (25%)
- 125 USDC (25%)
- 0.00025 ETH (25%)

Sponsor receives:
- 75 TRT (75%)
- 375 USDC (75%)
- 0.00075 ETH (75%)

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

  1. Select Rescue Type: Revoke Auth
  2. Enter Private Keys
    • Compromised: wallet whose delegation you want to revoke
    • Sponsor: wallet to pay for gas
  3. 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

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Tokens rescued: 1000 USDC

Fee: 1000 x 25% = 250 USDC
Net to Sponsor: 1000 - 250 = 750 USDC

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

  1. Private Keys are Confidential
    • Never share your private key with anyone
    • Harnsweep processes private keys client-side and does NOT store them
  2. Use a Separate Sponsor Wallet
    • Do not use your main wallet as the sponsor
    • Create a dedicated wallet for rescue operations
  3. Verify Transactions
    • Always check transactions on block explorer
    • Confirm assets have been transferred
  4. 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

Edit

Pub: 30 Apr 2026 06:56 UTC

Views: 38