Ethereum is a blockchain network; ETH is its native cryptocurrency, used to pay transaction fees and transfer value. Because ETH is widely traded and accepted across many crypto services, criminals may convert stolen assets into it as a liquid step in attempted laundering.
ETH transfers are recorded on a public blockchain, so conversion does not erase the transaction trail. However, rapid swaps, decentralized finance (DeFi) protocols, and cross-chain services can split or complicate that trail and make intervention harder. Defenders and investigators use blockchain analytics to follow funds, while exchanges and other service providers may flag or block transactions linked to identified addresses.