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Security AgentsWeb3 Auditor Agent

Web3 Auditor Agent

The Web3 Auditor is an enterprise-grade smart contract security agent that combines traditional static analysis with AI-powered economic risk assessment, gas optimization, and symbolic execution.

Overview

Category: Web3 & Blockchain Security Speed: less than 1 second per contract Scan Cost: 1 credit Supported Languages: Solidity, Rust, Move, Yul, Vyper Best For: Smart contract auditing, DeFi security, gas optimization

Key Features

🔍 Comprehensive Vulnerability Detection

  • OWASP Smart Contract Top 10 - Complete coverage of critical vulnerabilities
  • Oracle Manipulation - Flash loan attacks, price manipulation, stale data
  • Reentrancy Attacks - Cross-function and cross-contract reentrancy
  • Integer Overflow/Underflow - Arithmetic safety checks
  • Access Control - Permission vulnerabilities and privilege escalation
  • Input Validation - Missing zero checks, array bounds, parameter validation

⛽ Gas Optimization (Save $20-25/transaction)

The Web3 Auditor includes an AI-powered gas optimizer that finds 10 types of inefficiencies:

  1. Storage Layout - Packing variables, reducing SLOAD/SSTORE operations
  2. Redundant Operations - Duplicate calculations, unnecessary checks
  3. Loop Optimization - Caching array.length, reducing iterations
  4. Visibility Optimization - Using external vs public
  5. Data Types - uint256 vs uint8, bytes32 vs string
  6. State Variable Caching - Loading once vs multiple reads
  7. Short-Circuit Evaluation - Optimal condition ordering
  8. Unchecked Math - Safe arithmetic when overflow impossible
  9. Immutable Variables - Constants and immutables for cheaper reads
  10. Constant Variables - Compile-time constants

Real Savings Example:

// ❌ Before: ~50,000 gas
for (uint i = 0; i < recipients.length; i++) {
    balances[recipients[i]] += amounts[i];
}
 
// ✅ After: ~35,000 gas (30% reduction)
uint256 len = recipients.length;
for (uint i = 0; i < len; ++i) {
    unchecked {
        balances[recipients[i]] += amounts[i];
    }
}

Cost Savings at $2000 ETH, 50 gwei:

  • 15,000 gas saved = $1.50 per transaction
  • 1,000 transactions = $1,500 saved

🧠 Symbolic Execution with Z3

  • Path Condition Analysis - Explore all execution paths
  • Integer Bounds Checking - Prove arithmetic safety
  • Access Control Verification - Formal verification of permissions
  • State Consistency - Ensure invariants hold

💰 Economic Risk Assessment

Unique to Alprina - quantify the financial impact of vulnerabilities:

  • TVL-Adjusted Loss Estimates - Min-max dollar loss ranges
  • Protocol-Specific Risk Factors - Bridge (0.90), Lending (0.70), DEX (0.60)
  • Time-to-Exploit Assessment - Immediate, hours, days, weeks
  • Attack Complexity Analysis - Low, medium, high difficulty
  • Historical Exploit Database - 2016-2025 major hacks
  • Remediation Cost Estimates - Developer hours to fix

Example Risk Report:

Vulnerability: Oracle Manipulation (OWASP-SC-02)
TVL: $50M
Risk Score: 0.85 (HIGH)
Estimated Loss: $25M - $35M
Time to Exploit: Hours
Attack Complexity: Low
Historical Precedent: The Vow ($120M), BonqDAO ($120M)

🔗 Multi-Chain Support

  • Ethereum (Solidity, Yul, Vyper)
  • Solana (Rust)
  • Polygon, BSC, Arbitrum, Optimism
  • Aptos/Sui (Move)

📊 MEV & Flash Loan Analysis

  • MEV Extraction Risks - Sandwich attacks, frontrunning opportunities
  • Flash Loan Attack Vectors - Price manipulation, governance attacks
  • Cross-Contract Dependencies - Vulnerable external calls

Usage

Basic Smart Contract Scan

# Scan a single contract
alprina scan MyContract.sol
 
# Scan entire project
alprina scan ./contracts --type web3
 
# Specify blockchain
alprina scan ./contracts --chain ethereum

Gas Optimization

# Get gas optimization recommendations
alprina scan MyContract.sol --optimize-gas
 
# Apply gas optimizations automatically
alprina scan MyContract.sol --optimize-gas --apply-fixes
 
# Show gas savings report
alprina scan MyContract.sol --gas-report

Economic Risk Assessment

# Include economic impact analysis
alprina scan DeFiProtocol.sol --economic-risk --tvl 50000000
 
# Protocol-specific analysis
alprina scan LendingPool.sol --protocol-type lending

Symbolic Execution

# Run with Z3 symbolic execution (slower but thorough)
alprina scan MyContract.sol --symbolic-execution
 
# Focus on specific functions
alprina scan MyContract.sol --symbolic-function "withdraw"

Output Example

{
  "vulnerabilities": [
    {
      "type": "oracle_manipulation",
      "severity": "high",
      "title": "Spot Price Oracle Vulnerability",
      "line": 45,
      "function": "swap",
      "description": "Uses UniswapV2 spot price without TWAP protection",
      "economic_impact": {
        "estimated_loss_min": "$25M",
        "estimated_loss_max": "$35M",
        "tvl": "$50M",
        "risk_score": 0.85
      }
    }
  ],
  "gas_optimizations": [
    {
      "type": "storage_layout",
      "severity": "medium",
      "gas_saved": 15000,
      "eth_saved_per_tx": "0.00075 ETH",
      "usd_saved_per_tx": "$1.50"
    }
  ]
}

Detection Patterns

Oracle Manipulation (6 patterns)

  1. Chainlink Staleness - Missing updatedAt checks
  2. UniswapV2 Spot Price - Direct getReserves() usage
  3. Single Oracle Source - No price aggregation
  4. Pool Reserve Manipulation - Direct reserve access
  5. Flash Loan Price Impact - Within-transaction price usage
  6. Missing Circuit Breakers - No price bounds checking

Input Validation (5 patterns)

  1. Address Zero Checks - Missing require(addr != address(0))
  2. Amount Validation - Zero/negative amount checks
  3. Array Bounds - Missing length validation
  4. Unchecked External Calls - Missing return value checks
  5. Integer Overflow - Pre-Solidity 0.8.0 arithmetic

Best Practices

Before Mainnet Deployment

# Full audit with all checks
alprina scan ./contracts \
  --type web3 \
  --optimize-gas \
  --symbolic-execution \
  --economic-risk \
  --tvl 10000000
 
# Generate audit report
alprina report --format pdf --output audit-report.pdf

CI/CD Integration

# .github/workflows/security.yml
- name: Web3 Security Audit
  run: |
    alprina scan ./contracts --type web3 --fail-on high

Gas Optimization Workflow

# 1. Get recommendations
alprina scan MyContract.sol --optimize-gas > gas-report.txt
 
# 2. Review suggestions
cat gas-report.txt
 
# 3. Apply fixes (with backup)
alprina scan MyContract.sol --optimize-gas --apply-fixes
 
# 4. Run tests
forge test
 
# 5. Compare gas usage
forge snapshot --diff

Performance

  • Speed: less than 1 second per contract (without symbolic execution)
  • Accuracy: 85-95% confidence scores
  • Coverage: OWASP Smart Contract Top 10 + 50+ additional patterns
  • False Positives: under 5% (validated against real exploits)

Pricing

  • Basic Scan: 1 credit (~$0.10)
  • With Symbolic Execution: 2 credits (~$0.20)
  • With Economic Risk: Included (no extra cost)
  • Gas Optimization: Included (no extra cost)

Compare to traditional audits:

  • Manual audit: 10,000−10,000 - 50,000 (2-4 weeks)
  • Alprina Web3 Auditor: 0.10−0.10 - 0.20 (less than 1 second)

Historical Context

The Web3 Auditor’s detection patterns are based on analysis of major exploits:

ExploitDateLossPattern Detected
The VowAug 2024$120M+Oracle manipulation
BonqDAOFeb 2023$120MPrice oracle
MobyJan 2025-Flash loan oracle
Polter Finance2024-Price manipulation

Next Steps

Last updated on
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