TxBench: A Benchmark of Attack Transactions and Evidence-Backed Negatives on Seven EVM Chains

Dataset and pipeline, version 1.0. TxBench pairs 1,012 accepted attack transactions with 2,024 hard-benign negative transactions on Ethereum, BSC, Arbitrum, Base, Optimism, Polygon and Avalanche. Every transaction comes with its enriched trace (call, receipt, decoded logs and internal call tree). Each attack is checked on chain, its value is measured in USD by a value oracle, it carries evidence beyond its citation, and its weakness is mapped to OWASP's Smart Contract Weakness Enumeration (SCWE). The five-step pipeline that builds the benchmark from public sources is included and rebuilds every output offline, byte for byte. Validate with python3 validate.py; see README.md.