A computer science student needs to fill some information into a secured Adobe PDF job application that was received from a prospective employer. Instead of requesting a new document that allowed…

A man-in-the-middle attack involves intercepting and potentially modifying communications between two parties in transit; the student is attacking a local PDF file offline with no network session to intercept.

A brute-force attack systematically generates and tests every possible character combination within a defined character set and length range, whereas this script is constrained to a finite list of common passwords rather than exhaustive enumeration.

A dictionary attack uses a predefined list of probable passwords - in this case a list of commonly used passwords - and tests each entry sequentially against the target credential until a match is found or the list is exhausted. The student's script matches this definition exactly because the attempt space is limited to known common passwords rather than all possible character combinations. This approach is faster and more targeted than brute-force because it exploits the tendency of users to choose predictable or common passwords.

Session hijacking involves stealing or forging an authenticated session token to impersonate a legitimate user on an active network session; no live session or token exists when attacking an offline PDF file.