A system security engineer is preparing to conduct a security assessment of some new applications. The applications were provided to the engineer as a set that contains only JAR files. Which of the…

Launching the applications and applying dynamic analysis tools - including fuzz testing - exercises the actual runtime environment, exposing behaviors such as unexpected input handling, memory errors, and live system calls that static inspection of bytecode cannot reveal. Fuzz testing specifically stress-tests the application with malformed and boundary inputs, surfacing vulnerabilities like buffer overflows and injection flaws during execution. This provides a deeper and more accurate picture of security weaknesses than reviewing code alone.

A static code analyzer on JAR files works on compiled bytecode rather than source code, limiting the depth of analysis and missing runtime behaviors such as dynamic class loading or reflection-based vulnerabilities.

Decompiling JAR files produces only approximate source code with lost variable names and comments, and while useful for code review, it does not execute the application or reveal how it behaves under unexpected or malformed runtime inputs.

Reviewing the digital signing certificate reveals the publisher identity and trust chain but provides no information about the application's internal logic, code structure, or security weaknesses.