Final answer:
PowerShell's commonly abused keywords like Invoke-Expression, Set-ExecutionPolicy, EncodedCommand, and the WebClient class's DownloadString method, pose a security risk due to their potential in running arbitrary or hidden malicious code.
Step-by-step explanation:
Common Abused PowerShell Keywords
PowerShell is a versatile scripting language that can be used for automation and administrative tasks. However, it's often targeted by attackers seeking to exploit systems. Some of the common abused PowerShell keywords include Invoke-Expression, which can run arbitrary code passed as a string, making it a risk for executing malicious code. The Set-ExecutionPolicy cmdlet can be misused to lower security settings, allowing the execution of unsigned scripts. EncodedCommand, another keyword, can hide a script's contents and make it harder for security systems to detect malicious intent. Attackers also commonly utilize the DownloadString method of the WebClient class to download and execute scripts directly from a URL. It's important for system administrators to monitor the usage of these PowerShell keywords to help defend against attacks.