Malicious hashers can attempt to steal cryptocurrencies primarily by attacking the blockchain. A common method is the 51% attack, where they take control of more than 50% of the network's hashing power, allowing them to rearrange transactions and spend the same cryptocurrency multiple times (double-spending). They can also use malware to steal users' private keys, giving them access to those users' funds. “Phishing attacks” are another common method, where attackers trick users into revealing their sensitive information. Finally, some may create fraudulent cryptocurrency projects to defraud investors.