easyMultiple Choice
ISC2 CC Practice Question: A network administrator notices unusual traffic…
A network administrator notices unusual traffic from an internal workstation to an external IP address on port 443. The workstation has no business reason for such communication. Which action should the administrator take first?
⚠ Common exam trap
ISC2 often tests the principle of 'investigate before acting' to avoid destroying evidence, and the trap here is that candidates may choose a reactive security measure (like blocking or disabling) instead of following proper incident response procedures.
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
✓
Investigate the workstation for possible malware.
The first priority when encountering unexpected outbound traffic to an external IP on port 443 (HTTPS) is to investigate the workstation for possible malware. This traffic could indicate a command-and-control (C2) beacon or data exfiltration, and immediate investigation allows the administrator to gather forensic evidence before taking disruptive actions. Disabling the port or blocking traffic without investigation could destroy evidence or alert an attacker, while allowing the traffic would be negligent.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Disable the workstation's network port.
Why it's wrong here
Disabling the port severs connectivity before evidence is captured, destroying volatile data needed to scope the incident. It is tempting as a decisive containment step, and would be right once the threat is confirmed and isolation is required, but the first action should be investigation, not disconnection.
- ✗
Block all outbound traffic from that workstation immediately.
Why it's wrong here
Blocking all outbound traffic from the workstation is containment, not triage, and may tip off an attacker while erasing session evidence. It is tempting because rapid isolation limits damage, and would be correct after analysis confirms malicious command-and-control, but the first step is to investigate the traffic.
- ✓
Investigate the workstation for possible malware.
Why this is correct
Unusual outbound port 443 traffic from a workstation with no business justification suggests command-and-control or exfiltration activity. Investigating the host for malware establishes the cause before containment, satisfying the requirement to act first on a suspected compromised endpoint.
- ✗
Configure a firewall rule to allow the traffic and log it.
Why it's wrong here
Allowing the traffic lets potential exfiltration or command-and-control continue, and logging alone does not stop it. It is tempting because monitoring preserves evidence and avoids disrupting users, and would suit a sanctioned honeypot or known-good flow, but here it permits confirmed suspicious activity.
Go deeper
Related to this question
Learn chapter
Business Continuity and Disaster Recovery
Key term
Hypertext Transfer Protocol Secure
Hypertext Transfer Protocol Secure, or HTTPS, is the secure version of HTTP that encrypts data between a web browser and a website using SSL/TLS to protect sensitive information like passwords and credit card numbers.
Key term
Malware
Malware is any software intentionally designed to cause damage, disrupt operations, steal data, or gain unauthorized access to computer systems.
About these practice questions
One of 989 original CC practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. 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.