Sniffing, Social Engineering & DoS
34 free practice questions with explanations
PassNova has 34 free Certified Ethical Hacker (CEH) practice questions on Sniffing, Social Engineering & DoS, each with a clear explanation. Practise them in the browser with instant feedback — 100% free, no sign-up, on any device. Updated for 2026.
Sniffing, Social Engineering & DoS: example questions & answers
Here are 6 example questions from this topic. Practise the full set of 34 free in the browser.
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On a switched network, which attack floods the switch's CAM table to force it to behave like a hub, allowing the attacker to capture traffic?
- A DNS spoofing
- B Smurf attack
- C MAC flooding ✓
- D ARP poisoning
Answer: MAC flooding overwhelms the switch's limited CAM table so it fails open and broadcasts frames out all ports, letting the attacker sniff traffic not intended for them.
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In an ARP poisoning attack, what does the attacker send to associate their MAC address with the victim's or gateway's IP address?
- A TCP RST packets
- B Forged DNS responses
- C Gratuitous/spoofed ARP replies ✓
- D ICMP redirect messages only
Answer: The attacker sends spoofed ARP replies that map their own MAC address to a target IP (such as the default gateway), redirecting traffic through the attacker for a man-in-the-middle position.
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Which tool is the industry-standard packet analyzer used to capture and inspect network traffic in detail?
- A Wireshark ✓
- B Nessus
- C SQLmap
- D Hashcat
Answer: Wireshark is the de facto packet-capture and protocol-analysis tool, allowing deep inspection of individual frames and reassembled streams.
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A social-engineering email impersonates a bank and directs a specific senior executive to a fake login page. This targeted attack is best described as:
- A Shoulder surfing
- B Spear phishing (whaling when aimed at executives) ✓
- C Tailgating
- D Dumpster diving
Answer: Targeting a specific individual is spear phishing; when that individual is a high-value executive it is often called whaling. Both rely on tailored, deceptive messages.
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An attacker follows an authorized employee through a secured door without using their own credentials. This physical social-engineering technique is called:
- A Vishing
- B Pretexting
- C Phishing
- D Tailgating (piggybacking) ✓
Answer: Tailgating, also known as piggybacking, is the act of slipping through a controlled access point by closely following a legitimate, authorized person.
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In a SYN flood denial-of-service attack, what resource on the target is primarily exhausted?
- A Disk storage capacity
- B The table of half-open TCP connections (connection backlog) ✓
- C The DNS cache
- D The TLS certificate store
Answer: A SYN flood sends many SYN packets without completing the handshake, filling the server's backlog of half-open connections so it cannot accept legitimate requests.