Decentraland has a good reputation for security due to its use of the Ethereum blockchain. Since transactions are recorded on-chain, they're also verifiable and trackable. In addition, transactions are stored in a decentralized ledger, making them difficult to hack.
However, since it's an ERC20 token built on Ethereum's blockchain network, its security is still subject to that of Ethereum. If the blockchain were to suffer a successful attack, it could spell disaster for Decentraland's network as well.