If there’s one thing that’s abundant in the IT world, it is attacks and attackers. Attackers lurk almost everywhere. If you have computer systems, you can’t escape them. However, you can be proactive in identifying the different types of attacks and take steps to prevent them, or at least prevent their effectiveness. It’s important to realize that effective countermeasures exist for all of the attacks.
Attackers are actively working on beating the countermeasures. As they do, security professionals create additional countermeasures and the attackers try to beat them. The battle continues daily. If you’re planning to take the Security+ exam, you should have a basic understanding of various types of attacks from different sources and have some insight into preventing many of them.
For example, can you answer this question?
Q. Some protocols include timestamps and sequence numbers. What types of attacks do these components help protect against?
A. Smurf
B. Replay
C. Flood guards
D. Salting
More, do you know why the correct answer is correct and the incorrect answers are incorrect? The answer and explanation is available at the end of this post.
Security+ (SY0-601) Practice Test Questions
SY0-601 Practice Test Questions
Over 385 realistic Security+ practice test questions
At least 10 performance-based questions
All questions include explanations so you’ll know why the correct answers are correct,
and why the incorrect answers are incorrect.
Upgrade Your Resume with the Security+ New Version
Multiple quiz formats to let you use these questions based on the way you learn.
- Learn mode – randomized. View each of the questions in random order. Learn mode allows you to keep selecting answers until you select the correct answer. Once you select the correct answer, you’ll see the explanation. Click here to see how learn mode works.
- Test mode – randomized. View each of the questions in random order. In test mode, you can only see the correct answers and explanations after you complete the test. Click here to see how test mode works.
- Test mode – 75 random questions. View 75 random questions from the full test bank similar to how the Security+ exam has a potential maximum of 75 multiple choice questions.
Pass the First Time You Take It
Get the full bank of SY0-601 Practice Test Questions Here
Click here if you’re looking for SY0-501 Online Study Package
Replay Attacks
A replay attack is one where an attacker replays data that was already part of a communication session. In a replay attack, a third party attempts to impersonate a client that is involved in the original session. Replay attacks can occur on both wired and wireless networks.

As an example, Maggie and Bart may initiate a session with each other. During the communication, each client authenticates with the other by passing authentication credentials to the other system. Hacker Harry intercepts all the data, including the credentials, and later initiates a conversation with Maggie pretending to be Bart. When Maggie challenges hacker Harry, he sends Bart’s credentials.
Many protocols use timestamps and sequence numbers to thwart replay attacks. For example, Kerberos helps prevent replay attacks with timestamped tickets.
Remember this
Replay attacks capture data in a session with the intent of later impersonating one of the parties in the session. Timestamps and sequence numbers are effective countermeasures against replay attacks.
CompTIA Security+ Study Guide
The
CompTIA Security+: Get Certified Get Ahead: SY0-601 Study Guide
is an update to the top-selling SY0-201, SY0-301, SY0-401, and SY0-501 study guides, which have helped thousands of readers pass the exam the first time they took it. It includes the same elements readers raved about in the previous four versions.
Each of the eleven chapters presents topics in an easy to understand manner and includes real-world examples of security principles in action.
You’ll understand the important and relevant security topics for the Security+ exam, without being overloaded with unnecessary details. Additionally, each chapter includes a comprehensive review section to help you focus on what’s important.

Over 300 realistic practice test questions with in-depth explanations will help you test your comprehension and readiness for the exam. The book includes:
- A 75 question pre-test
- A 75 question post-test
- Practice test questions at the end of every chapter.
Each practice test question includes a detailed explanation to help you understand the content and the reasoning behind the question. You’ll be ready to take and pass the exam the first time you take it.
If you plan to pursue any of the advanced security certifications, this guide will also help you lay a solid foundation of security knowledge. Learn this material, and you’ll be a step ahead for other exams. This SY0-601 study guide is for any IT or security professional interested in advancing in their field, and a must-read for anyone striving to master the basics of IT security.
Kindle edition also available.
Xmas Attacks
The Xmas attack, also called a Christmas tree attack, is a type of port scan used to identify underlying details of an operating system. For example, it can help determine if the scanned system is running a Microsoft-based operating system or a Linux-based operating system.
A typical port scan attempts to learn what ports are open on a system. Based on what ports are open, the port scanner can detect what services and protocols are running on a system. For example, if port 80 is open, it’s very likely that the Hypertext Transfer Protocol (HTTP) protocol is running on the system because the well-known port for HTTP is port 80.
However, the Xmas attack goes farther than a typical port scan. It has several bits set in the packet header and is reminiscent of lights lit in a Christmas tree. As least someone thought it looked like a Christmas tree and decided to name it a Christmas tree attack, or Xmas attack.
More importantly, the Xmas attack sets specific flags within the TCP packet header. Different operating systems respond to these flags in specific ways. Attackers can analyze the response and determine the operating system of the remote system in addition to what ports are open. In many cases, the attacker can even determine the version of the responding system.
The Xmas attack is often used as reconnaissance in an overall attack. It doesn’t cause damage itself. However, attackers use the information they gain from the Xmas attack to launch other attacks. Most intrusion detection systems (IDSs) and intrusion prevention systems (IPSs) can detect these attacks.
CompTIA Security+ Study Guide
The
CompTIA Security+: Get Certified Get Ahead: SY0-601 Study Guide
is an update to the top-selling SY0-201, SY0-301, SY0-401, and SY0-501 study guides, which have helped thousands of readers pass the exam the first time they took it. It includes the same elements readers raved about in the previous four versions.
Each of the eleven chapters presents topics in an easy to understand manner and includes real-world examples of security principles in action.
You’ll understand the important and relevant security topics for the Security+ exam, without being overloaded with unnecessary details. Additionally, each chapter includes a comprehensive review section to help you focus on what’s important.

Over 300 realistic practice test questions with in-depth explanations will help you test your comprehension and readiness for the exam. The book includes:
- A 75 question pre-test
- A 75 question post-test
- Practice test questions at the end of every chapter.
Each practice test question includes a detailed explanation to help you understand the content and the reasoning behind the question. You’ll be ready to take and pass the exam the first time you take it.
If you plan to pursue any of the advanced security certifications, this guide will also help you lay a solid foundation of security knowledge. Learn this material, and you’ll be a step ahead for other exams. This SY0-601 study guide is for any IT or security professional interested in advancing in their field, and a must-read for anyone striving to master the basics of IT security.
Kindle edition also available.
Man-in-the-Middle Attacks
A man-in-the-middle (MITM) attack is a form of active interception or active eavesdropping. It uses a separate computer that accepts traffic from each party in a conversation and forwards the traffic between the two. The two computers are unaware of the MITM computer, and it can interrupt the traffic at will or insert malicious code.
For example, imagine that Maggie and Bart are exchanging information with their two computers over a network. If hacker Harry can launch an MITM attack from a third computer, he will be able to intercept all traffic. Maggie and Bart still receive all the information, so they are unaware of the attack. However, hacker Harry also receives all the information. Because the MITM computer can control the entire conversation, it is easy to insert malicious code and send it to the computers. The ARP Poisoning Attacks blog post shows how ARP poisoning can be used to launch an MITM attack.
Kerberos helps prevent man-in-the-middle attacks with mutual authentication. It doesn’t allow a malicious system to insert itself in the middle of the conversation without the knowledge of the other two systems.
Full Security+ Course
SY0-601 Full Security+ Course
Helping you Pass the First Time
This course includes all of the multiple-choice practice test questions, performance-based questions, audio, and flashcards from the but adds the CompTIA Security+: Get Certified Get Ahead: SY0-601 Study Guide within an online course.
Test your readiness with these quality materials
Here’s what you get
Random 75-question tests
Random practice tests from the all of the practice test questions in the
CompTIA Security+: Get Certified Get Ahead: SY0-601 Study Guide. All questions include explanations so you’ll know why the correct answers are correct, and why the incorrect answers are incorrect.
Performance-based Questions
These questions show you what you can expect in the live exam. They include drag and drop, matching, sorting, and fill in the blank questions.
Online Flashcard Set
Audio – SY0-601 Security+ Remember This Audio Files
Learn by Listening (MP3 downloads.)
Audio – SY0-601 Security+ Question and Answer Audio Files
Learn by Listening (MP3 downloads.)Bonus #1
The same set of questions organized by domain including questions in the
CompTIA Security+: Get Certified Get Ahead: SY0-601 Study Guide plus extra practice test questions.
Bonus #2
Audio from the end of chapter reviews from each of the chapters in the
CompTIA Security+: Get Certified Get Ahead: SY0-601 Study Guide.
Bonus #3
Access to all of the online content that is available for free to anyone that purchases the CompTIA Security+: Get Certified Get Ahead: SY0-601 Study Guide. This includes labs, extra practice test questions, and supplementary materials.Bonus #4
Extended access. Access the study materials for a total of 60 days because sometimes life happens.Bonus #5
10% off Voucher Code. Access to a coupon code that will give you 10% off your exam voucher. At the current price of $370 USD for the Security+ voucher, this can save you $37.Get the SY0-601 Full Security+ Course Here
Q. Some protocols include timestamps and sequence numbers. These components help protect against what type of attacks?
A. Smurf
B. Replay
C. Flood guards
D. Salting
Answer is B. Timestamps and sequence numbers act as countermeasures against replay attacks.
Blocking directed broadcasts prevents smurf attacks.
Flood guards protect against SYN (synchronize) attacks.
Salting protects against brute force attacks on passwords.
See Chapter 7 of the CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide for more information identifying advanced attacks.