200-201 Security Monitoring Practice Question
During packet analysis in Wireshark, which THREE findings are indicators of potential malicious activity? (Choose THREE.)
⚠ Common exam trap
Cisco often tests the distinction between normal traffic patterns and protocol anomalies; the trap here is that candidates may overlook the 'unusually large' qualifier and dismiss ICMP anomalies as benign, or mistake a legitimate HTTPS connection for suspicious activity due to encryption.
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
✓
An unusually large ICMP echo request packet (e.g., 65,000 bytes).
An unusually large ICMP echo request packet, such as 65,000 bytes, exceeds the maximum allowed size for a standard ICMP packet (typically 65,535 bytes total including headers, but the data payload should not exceed 65,527 bytes). This oversized packet is a classic indicator of a 'Ping of Death' attack, where the attacker sends a malformed packet that causes a buffer overflow on the target system, leading to a crash or remote code execution. In Wireshark, such an anomaly stands out against normal ICMP traffic, which usually has a small payload (e.g., 32 or 56 bytes).
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
An HTTPS connection to a well-known website.
Why it's wrong here
HTTPS to legitimate sites is normal.
- ✓
An unusually large ICMP echo request packet (e.g., 65,000 bytes).
Why this is correct
Large ICMP packets could indicate a ping flood or covert channel.
- ✓
Unencrypted credentials in an HTTP packet.
Why this is correct
Credentials sent in cleartext over HTTP can be intercepted.
- ✗
A normal DNS query for a common domain.
Why it's wrong here
Common DNS queries are benign.
- ✓
A large number of TCP SYN packets to various ports on one host.
Why this is correct
This indicates a port scan.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 200-201 practice question is part of Courseiva's free Cisco 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 200-201 exam.