CPENT Iot And OT Exploitation Practice Question
An analyst is reviewing PCAP files captured from an ICS environment where Modbus/TCP traffic is flowing. The analyst notices cleartext commands being sent to alter coil values. Which tool can the analyst use to automatically extract Modbus registers and visualize the register state changes over time from the PCAP file?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Wireshark
Wireshark includes built-in dissectors for Modbus/TCP and filters that allow inspecting every register read/write operation, making it the primary tool for packet-level ICS analysis.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
John the Ripper
Why it's wrong here
John the Ripper is an offline password cracking utility.
- ✓
Wireshark
Why this is correct
Wireshark decodes Modbus/TCP packets natively, allowing the analyst to filter by 'modbus' and view function codes, reference numbers, and register values.
- ✗
Hashcat
Why it's wrong here
Hashcat is an advanced password recovery tool utilizing GPU acceleration.
- ✗
Dirb
Why it's wrong here
Dirb is a web content scanner used to find hidden directories on web servers.
Visual reference
About these practice questions
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official EC-Council exam blueprint
This CPENT practice question is part of Courseiva's free EC-Council certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CPENT exam.