Which tool is commonly used by threat actors on a webpage to take advantage of the softwarevulnerabilitiesof a system to spread malware?

Exploit kits such as Angler, RIG, and Magnitude are deployed on malicious or compromised web pages and silently probe client-side software (browsers, Java, Flash, PDF readers) for unpatched vulnerabilities. When a vulnerability is found, the kit automatically delivers and executes a malware payload without user interaction, making them the primary web-based vector for drive-by downloads.

A rootkit is malware that hides its presence and other malicious activity on an already-compromised system - it is not a tool used on a webpage to exploit visitors.

A 'vulnerability kit' is not a recognized term in the security industry and does not describe any standard attack category or tool.

'Script kiddie kit' is not a defined security term - 'script kiddie' describes an unskilled attacker, but there is no corresponding toolkit category with that name.