ISC2 CC Network Security Practice Question
A security analyst notices unusual traffic on the network. Using Wireshark, they capture packets and see that an attacker is reading all unencrypted data from the network segment. Which type of attack is most likely being performed?
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
✓
Sniffing / Eavesdropping
Sniffing or eavesdropping involves capturing network traffic to read data. In this scenario, unencrypted data is being read, which is characteristic of sniffing.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Spoofing
Why it's wrong here
Spoofing falsifies a source address or identity to impersonate a trusted host; it does not itself read unencrypted data from the segment. It is tempting because spoofing often accompanies sniffing, and it is the right answer when the evidence shows forged addresses or impersonated identities rather than passive capture.
- ✗
DoS
Why it's wrong here
A DoS attack floods a target to exhaust its resources and deny service; it does not read unencrypted data off the segment. It is tempting because DoS also generates unusual traffic visible in Wireshark, and it is the right answer when the symptom is service unavailability rather than data disclosure.
- ✓
Sniffing / Eavesdropping
Why this is correct
Sniffing passively captures frames traversing a shared segment, letting the attacker read unencrypted payloads without altering traffic. This matches the stem's evidence: Wireshark shows data being read, not modified or blocked. Eavesdropping requires no injection or spoofing, only promiscuous-mode capture on the segment.
- ✗
Man-in-the-middle
Why it's wrong here
A man-in-the-middle attack intercepts and relays traffic between two parties, typically altering or injecting it, rather than passively reading all broadcast data on the segment. It is tempting because MitM also exposes unencrypted data, and it is correct when the attacker sits between endpoints and relays their communications.
Go deeper
Related to this question
About these practice questions
Courseiva writes every CC question from scratch — 989 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CC practice question is part of Courseiva's free ISC2 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 CC exam.