Unauthorized System Access

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Do you know a malware type that allows attackers to access systems from remote locations? You should if you plan to take the Security+ exam.  This post should help.

Here is a sample practice test question:

Q. A recent antivirus scan on a server detected a Trojan. A technician removed the Trojan, but a security administrator expressed concern that unauthorized personnel might be able to access data on the server. The security administrator decided to check the server further. Of the following choices, what is the administrator MOST likely looking for on this server?

A. Backdoor

B. Logic bomb

C. Rootkit

D. Botnet

Can you answer this question? 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.

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Backdoors

A backdoor provides another way of accessing a system, similar to how a backdoor in a house provides another method of entry. Malware such as Trojans often install backdoors on systems to bypass normal authentication methods.

Application developers often code backdoors into applications, but this practice is not recommended. For example, an application developer might create a backdoor within an application intended for maintenance purposes. However, if attackers discover the backdoor, they can use it to access the application.

Unauthorized System Access

 

Effective account management policies help prevent ex-employees from creating backdoors after they are fired. For example, if an employee loses network access immediately after being fired, the employee cannot create a backdoor account. In contrast, if an administrator retains network access, he has the opportunity to create another administrative account that he can use even if his original account is disabled. That’s exactly what a Fannie Mae Unix engineer did after being told he was fired.

Fannie Mae’s account management policy did not revoke his elevated system privileges right away, giving him time to create a backdoor account. After going home, he accessed the system remotely and installed a logic bomb script scheduled to run at 9:00 a.m. on January 31. If another administrator hadn’t discovered the logic bomb, it would have deleted data and backups for about four thousand servers, changed their passwords, and shut them down.

Remember this

A backdoor provides another of way of accessing a system. Many types of malware create backdoors, allowing attackers to access systems from remote locations. Employees have also created backdoors in applications and systems.

CompTIA Security+ Study Guide (SY0-401)

The 401 Version of the Study Guide is Now Available

SY0-401 Study GuideThe CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide is an update to the top-selling SY0-201 and SY0-301 study guides, which have helped thousands of readers pass the exam the first time they took it.

CompTIA Authorized Quality Content (CAQC)After a comprehensive review by ProCert Labs, the SY0-401 version has been certified as CompTIA Approved Quality Content (CAQC) and covers every aspect of the SY0-401 exam.

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Over 400 realistic practice test questions with in-depth explanations will help you test your comprehension and readiness for the exam. The book includes:

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Botnets

A botnet combines the words robot and network. It includes multiple computers that act as software robots and function together in a network (such as the Internet), often for malicious purposes. The computers in a botnet are called zombies and they will do the bidding of whoever controls the botnet.

Bot herders are criminals who manage botnets. They attempt to infect as many computers as possible and control them through one or more servers running command-and-control software. The infected computers periodically check in with the command-and-control servers, receive direction, and then go to work. The user is often unaware of the activity.

Most computers join a botnet through malware infection. For example, a user could download pirated software with a Trojan or click a malicious link, resulting in a drive-by download. The malware then joins the system to a botnet.

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Online access includes all of the content from the

CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide

  • Introduction
  • About the exam (including types of questions and strategies for performance-based questions)
  • 100 question pre-assessment exam
  • Mastering Security Basics (full content from Chapter 1 of the study guide including the exam topic review and 20 practice test questions)
  • Exploring Control Types and Methods (full content from Chapter 2 of the study guide including the exam topic review and 20 practice test questions)
  • Understanding Basic Network Security (full content from Chapter 3 of the study guide including the exam topic review and 20 practice test questions)
  • Securing Your Network (full content from Chapter 4 of the study guide including the exam topic review and 20 practice test questions)
  • Securing Hosts and Data (full content from Chapter 5 of the study guide including the exam topic review and 20 practice test questions)
  • Understanding Malware and Social Engineering (full content from Chapter 6 of the study guide including the exam topic review and 20 practice test questions)
  • Identifying Advanced Attacks (full content from Chapter 7 of the study guide including the exam topic review and 20 practice test questions)
  • Managing Risk (full content from Chapter 8 of the study guide including the exam topic review and 20 practice test questions)
  • Preparing for Business Continuity (full content from Chapter 9 of the study guide including the exam topic review and 20 practice test questions)
  • Understanding Cryptography (full content from Chapter 10 of the study guide including the exam topic review and 20 practice test questions)
  • Exploring Operational Security (full content from Chapter 11 of the study guide including the exam topic review and 20 practice test questions)
  • 100 question post-assessment exam
  • Security+ Acronyms

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Test your readiness with these quality materials

Random 100-question tests

Random practice tests from the all of the practice test questions in the CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide. All questions include explanations so you'll know why the correct answers are correct, and why the incorrect answers are incorrect.

34 Simulated Performance-based Questions

Eight sets of performance-based questions with multiple questions in each set. These questions help you understand and prepare for performance based questions.

22 Realistic Performance-based Questions

Two new sets of performance-based questions with a total of 22 questions. These new questions use a new testing engine that includes realistic drag and drop, matching, sorting, and fill in the blank questions.

Flashcard Set

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Subnetting mini-tutorial that will help you answer two key question types:
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As an example, Coreflood malware is a Trojan horse that opens a backdoor on compromised computers. Authorities shut down the Coreflood botnet in April 2011, and its command-and-control servers managed about 2.3 million computers at that time. Experts estimate they had stolen between $10 million and $100 million before authorities shut them down.

Infecting 2.3 million computers and stealing tens of millions of dollars draws a lot of attention. To avoid attention, many botnets manage fewer than 50,000 computers and fly under the radar of most authorities. The result is the same for the victims, though. It doesn’t matter if victims are robbed by a huge botnet or a smaller botnet; they have still been robbed.

Botnet herders sometimes maintain complete control over their botnets. Other times, they rent access out to others to use as desired. Some of the instructions sent by the command-and-control servers include:

  • Send spam.
  • Launch a distributed denial-of-service attack.
  • Download additional malware, adware, or spyware such as keyloggers.

Security+ Practice Test Questions

SYO-401 Practice Test Questions Now Available

Over 440 realistic Security+ practice test questions

All questions include explanations so you'll know why the correct answers are correct,

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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.
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  • Test mode - 100 random questions. View 100 random questions from the full test bank similar to how the Security+ exam has a potential maximum of 100 multiple choice questions. 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.

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 SYO-401 Practice Test Questions Now Available


INCLUDES QUESTIONS TO HELP YOU PREPARE

FOR THE NEW PERFORMANCE BASED QUESTIONS 

Bonus - Performance Based Questions

Additional Security+ questions to help you prepare for the new performance based questions. These are included with the full bank of Security+ practice test questions and are divided into different sections. For example, you'll have access to the following links:

- Performance Based Question - Set 1

You'll see a graphic explaining what you might be required to do on the actual exam to match different types of security to mobile devices and servers in a data center. You'll then have two questions that test your knowledge and ability to correctly answer the questions. This question also includes a link to a graphic showing the end solution for the overall performance based question simulation.

- Performance Based Question - Set 2

You'll see a graphic explaining what you might be required to do on the actual exam to match different types of attacks with the name of the attack type. You'll then have five questions that test your knowledge and ability to correctly answer the questions. This question also includes a link to a graphic showing the end solution for the overall performance based question simulation.

- Performance Based Question - Set 3

You'll see a graphic showing a network with computers and servers separated by a firewall. The firewall is used to control traffic between the computers and users using rules within an access control list (ACL).  You'll have three questions that test your knowledge and ability to correctly identify the relevant components of the rule. The incorrect answers and explanation provide you with insight into how to correctly answer this type of question on the actual exam.

- Performance Based Question - Set 4

You'll see a graphic explaining what you might be required to do on the actual exam related to what a forensic analyst would do during an investigation. You'll then have two questions that test your knowledge and ability to correctly answer the questions. This question also includes a link to a graphic showing the end solution for the overall performance based question simulation.

- Performance Based Question - Set 5

You'll see a graphic explaining what you might be required to do on the actual exam to match protocols and ports. You'll then have seven questions that test your knowledge and ability to correctly answer the questions. This question also includes a link to a graphic showing the end solution for the overall performance based question simulation.

- Performance Based Question - Set 6

You'll see a list of security controls along with a graphic showing devices and locations within an organization, along with instructions on what you might be required to do on the actual exam to match the controls with the devices and locations. You'll then have four questions that test your knowledge and ability to correctly answer the questions. This question also includes a link to a graphic showing the end solution for the overall performance based question simulation.

- Performance Based Question - Set 7

You'll see a list of authentication methods and authentication factors along with instructions on what you might be required to do on the actual exam to match the authentication methods with the authentication factors. You'll then have six questions that test your knowledge and ability to correctly answer the questions. This set also includes a link to a graphic showing the end solution for the overall performance based question simulation.

- Performance Based Question - Set 8

You'll see a graphic explaining what you might be required to do on the actual exam to match different types of attacks with the name of the attack type. You'll then have five questions that test your knowledge and ability to correctly answer the questions. This is similar to Set 2 but expands on the possibilities. The set also includes a link to a page showing the end solution for the overall performance based question simulation.

New - Performance Based Question - Set 9

New questions recently added using a different testing engine. See a demo here. This set includes drag and drop and matching questions on ports.

New - Performance Based Question - Set 10

A random set of 20 performance-based questions using drag and drop, matching, sorting, and fill in-the blank. This set includes performance-based questions on RAID.

Get the full bank of Security+ Practice Test Questions Here

Get the full bank of Security+ Practice Test Questions

Polymorphic Malware

Some virus developers use polymorphism as a method of armor. Polymorphic malware has the ability to morph or mutate when it replicates itself, or when it executes. The goal is to create a virus or other malware with enough variations that AV software cannot detect it as the same malware. Over time, a single malware file could have thousands of variants.

Virus developers typically encrypt polymorphic viruses as an additional layer of armor to evade detection by AV software. The virus includes a decryption method that executes when the file executes. A common polymorphic technique is to vary the encryption/decryption method slightly. This method retains the original malicious code, but modifies the file enough to make it difficult to detect.


 

Q. A recent antivirus scan on a server detected a Trojan. A technician removed the Trojan, but a security administrator expressed concern that unauthorized personnel might be able to access data on the server. The security administrator decided to check the server further. Of the following choices, what is the administrator MOST likely looking for on this server?

A. Backdoor

B. Logic bomb

C. Rootkit

D. Botnet

Answer is A. The security administrator is most likely looking for a backdoor because Trojans commonly create backdoors, and a backdoor allows unauthorized personnel to access data on the system.

Logic bombs and rootkits can create backdoor accounts, but Trojans don’t create logic bombs and would rarely install a rootkit.

The computer might be joined to a botnet, but it wouldn’t be a botnet.

See Chapter 6 of the CompTIA Security+: Get Certified Get Ahead: SY0-401 Study Guide for more information on malware types.

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