Quick Answer
The answer is SMB, as port 445 is the default port for Microsoft-DS, which directly hosts the Server Message Block (SMB) protocol over TCP/IP for file and printer sharing. This technical concept is critical for SMB protocol port 445 traffic analysis because SMB normally operates within a local network; unusual outbound traffic to an external IP on this port strongly suggests a workstation is attempting to connect to a remote share, which in a security context may indicate data exfiltration or lateral movement. On the Systems Security Certified Practitioner SSCP exam, this question tests your ability to map common ports to protocols and recognize anomalous behavior—a core skill in network monitoring and incident response. A common trap is confusing port 445 with port 139 (NetBIOS), but remember that port 445 is SMB over TCP without NetBIOS, while port 139 uses NetBIOS. Memory tip: “445 is SMB direct—no NetBIOS, no redirect.”
This SSCP practice question tests your understanding of network and communications security. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
An analyst notices unusual outbound traffic from a workstation to an external IP on port 445. Which protocol is likely being used?
HTTP
Why wrong: HTTP typically uses port 80 or 8080.
SMB
SMB uses port 445 for direct TCP communication, often associated with file sharing.
FTP
Why wrong: FTP uses ports 20 and 21.
DNS
Why wrong: DNS uses port 53.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
SMB
Port 445 is the default port for Microsoft-DS (Direct Hosting of SMB over TCP/IP), which is used by the Server Message Block (SMB) protocol for file and printer sharing. Unusual outbound traffic on this port often indicates SMB activity, such as a workstation attempting to connect to a remote share or, in a security context, potential data exfiltration or lateral movement using SMB.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
HTTP
Why it's wrong here
HTTP typically uses port 80 or 8080.
SMB
Why this is correct
SMB uses port 445 for direct TCP communication, often associated with file sharing.
Related concept
Read the scenario before looking for a memorised answer.
FTP
Why it's wrong here
FTP uses ports 20 and 21.
DNS
Why it's wrong here
DNS uses port 53.
Common exam traps
ISC2 often tests the association of well-known ports with their protocols, and the trap here is that candidates may confuse port 445 with NetBIOS (ports 137-139) or assume SMB only uses ports 137-139, forgetting that modern SMB over TCP/IP uses port 445 directly.
Detailed technical explanation
SMB over TCP/IP (NetBIOS-less) uses port 445 directly, bypassing the legacy NetBIOS over TCP/IP (ports 137-139). Under the hood, SMB operates as a request-response protocol, and outbound traffic on port 445 from a workstation could indicate an attempt to mount a remote share or, in a real-world attack scenario, the use of tools like PsExec or EternalBlue to propagate malware laterally. Security analysts often monitor this port for signs of unauthorized data transfer or ransomware activity.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A security analyst at a medium-sized enterprise encounters this scenario during an investigation or architecture review. The correct answer reflects best practice for the specific threat or control described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Security exam questions test whether you can match controls to threats in context — not just recall definitions.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Network and Communications Security — study guide chapter
Learn the concepts, then practise the questions
Network and Communications Security practice questions
Targeted practice on this topic area only
All SSCP questions
504 questions across all exam domains
Systems Security Certified Practitioner SSCP study guide
Full concept coverage aligned to exam objectives
SSCP practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise SSCP questions linked to Risk Identification, Monitoring and Analysis.
Practise SSCP questions linked to Network and Communications Security.
Practise SSCP questions linked to Systems and Application Security.
Practise SSCP questions linked to Security Operations and Administration.
Practise SSCP questions linked to Incident Response and Recovery.
Practise SSCP questions linked to Access Controls.
Practise SSCP questions linked to Cryptography.
Practise SSCP questions linked to SSCP fundamentals.
Practise SSCP questions linked to SSCP scenario.
Practise SSCP questions linked to SSCP troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Network and Communications Security — This question tests Network and Communications Security — Read the scenario before looking for a memorised answer..
The correct answer is: SMB — Port 445 is the default port for Microsoft-DS (Direct Hosting of SMB over TCP/IP), which is used by the Server Message Block (SMB) protocol for file and printer sharing. Unusual outbound traffic on this port often indicates SMB activity, such as a workstation attempting to connect to a remote share or, in a security context, potential data exfiltration or lateral movement using SMB.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 30, 2026
This SSCP 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 SSCP exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.