A crypto drainer is a type of fraudulent software / script designed to exploit vulnerabilities in dApps, smart contracts, or wallets. By manipulating wallet connections through phishing sites or malicious contracts, the drainer initiates unauthorized transactions by gaining access to the wallet’s private key or permissions. Once a victim unknowingly authorizes the smart contract interaction (a “connect” or “approve” function), the drainer executes automated functions, siphoning off crypto from the wallet through methods such as token transfers, swaps, or multicalls, bypassing security checks due to the initial permission granted by the victim.