A common misconception about security that hackers hope you don't know is that NoSQL databases, such as MongoDB, are not vulnerable to SQL injection attacks because they do not use SQL. However, this is incorrect, and hackers have developed tools like NoSQLmap to exploit vulnerabilities in NoSQL applications. Another misconception is that authentication is only necessary for public networks, but social engineering attacks can be used to gain access even when the network is private. Additionally, many people believe that encryption at rest will protect their data from hackers, but this is not always the case, as key management interoperability protocols are often overlooked. Finally, malicious insiders, such as employees who may accept a job with a competitor and bring sensitive information with them, pose a significant risk to businesses. Using secure by default configurations, like those provided by MongoDB Atlas, can help mitigate these risks.