Trường ĐH Khoa học Huế ĐỀ KIỂM TRA ĐỊNH KỲ
Khoa CNTT Môn: An Toàn Mạng
Lớp: …..…- Th/gian: ……..
Họ và tên SV:…………………………………………Lớp:……………………………...
Phần trả lời trắc nghiệm:
Câu Đáp án Câu Đáp án G. chú Câu Đáp án G. chú
a 1 11
b 2 12
c 3 13
d 4 14
e 5 15
f 6 16
g 7 17
h 8 18
i 9 19
j 10 20
Phần câu hỏi và trả lời tự luận: Giải thích rõ (ngắn gọn) các câu sau: ………………
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SUMMARY
Historical Hacking Techniques:
• The original (đầu tiên) intent (mục tiêu) of the Internet was to
share resources openly between research institutions.
• Some of the first hackers used the Network File System (NFS) to gain (giành
quyền) access to information.
• rlogin was commonly used by administrator and users to enter remote systems
without a password.
• Cracking weak passwords or short passwords using brute-force methods is
one of the most common ways hackers gain access to systems.
• Some weak passwords fall into the bad configuration category because a
developer will use a simple password that matches the ID for example, a user ID and
password that are both jdoe.

• Alternatives to bad password are the use of smart cards or biometrics (sinh
trắc học) .
• Programming flaws are another method hackers use to exploit (khai thác)
computer systems.
• Hackers use buffer overflows to inundate (tràn ngập) the target system,
causing it to crash or run commands to elevate privileges to the system.
• Denial of service (DoS) is used by hackers to render the target unusable.
• Distributed denial of service (DDoS) can be targeted toward a large number
of systems.
• DDoS attacks have three-tiered architecture using the master, slave, and
client processes that have been installed on compromised (thoả hịêp/tổn thương) systems.
Advanced Techniques:
• Sniffers are used by hackers to collect information about a target network or
system.
• Sniffing a switched network is harder than a network that uses hubs.
• The hacker must do one of two things to sniff a switched network: convince
(thuyết phục) the switch to send the traffic to it or cause the switch to send traffic to all
ports.
• The switch can be fooled (bị đánh lừa) to send traffic to the sniffer by
duplicating the MAC or spoofing the ARP or DNS.
• In order for ARP spoofing (giả mạo) to be effective, the sniffer must have the
capability to forward the traffic on to the correct destination.
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• To accomplish (thực hiện) attacks by sniffing, the attacker must have a system
on the local switch.
• IP spoofing makes it more difficult to track an attacker.
• Using IP spoofing, the attacker cannot see the target’s responses to his actions.
Identify Malicious (có hại) Code:
• Viruses are not structured to exist by themselves.
• Initially, viruses attached themselves to executable files.

• Viruses first appeared when the majority of the computer used the Disk
Operating System (DOS).
• Macro viruses attach themselves to word processing documents.
• Trojan horse damage can be similar to that of computer viruses.
• Worms travel from system to system without the assistance (trợ giúp) of the
user.
• The Slapper worm uses a peer-to-peer model.
• Attackers combine two types of malicious code to accomplish multiple roles.
Identify Methods of the Untargeted Hacker:
• The untargeted hacker is not looking (chú ý) to access a particular system.
• Reconnaissance (thăm dò) for an untargeted hacker can take many forms.
• Untargeted attackers will use a stealth scan to identity what systems are up.
• The reset scan is a variation of a stealth scan.
• Telephone reconnaissance (war-dialing) is used to identity potential victims
(nạn nhân).
• Attackers look for wireless network by war-driving.
• The untargeted hackers will have a single exploit or a small group of exploits
available.
• More sophisticated (tinh vi) hackers use reconnaissance tools to identity
multiple vulnerability (dễ bị tấn công/“yếu”) systems and then write scripts to allow them
to exploit all the systems in a short amount of time.
Identify Methods of the Targeted Hacker:
• Targeted hackers are motivated by the desire for something an organization
has.
• The target for this attacker is chosen for a reason.
• Address reconnaissance is used to identify the address space used by the target
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organization.
• Attackers can find more information on addresses in use at the target by doing
a zone transfer from the primary DNS.

• Phone reconnaissance is more difficult than identifying network addresses
associated with a target.
• The hacker, in addition to looking for phone numbers associated with the
target’s computer systems, would also check to see if to the target is using or misusing
wireless.
• Attacker will use ping sweeps to find open ports.
• Vulnerability identification is potentially the most dangerous for the hacker in
that there is a potential for being detected while identifying vulnerabilities.
• The hacker needs to understand the business of target to know how they use
computer systems and what would hurt the target the most.
• A targeted hacker may use physical reconnaissance to gain access to systems or
information they want (for example, watching the building for opportunities to enter or
examining the trash).
• The targeted hacker will use a flaw in physical access to gain entry to the site.
• The hacker will use the information gathered to choose the best method of
access without being detected.
• The hacker will know enough information to map external systems and all
connection to internal systems.
• The attacker will attempt to cover up the intrusion by editing the logs to
remove the entries related to the break-in.
• The easiest physical attack is to examine the contents of the organization’s
trash.
• Social engineering is the safest physical attack and can lead to electronic
access.
• The most dangerous physical access is the physical penetration of the site.
Key Terms:
ARP spoofing ; buffer overflow ; denial of service (DoS)
DNS spoofing ; hacktivism ; hybrid malicious code
IP spoofing ; MAC duplicating ; malicious code
Ping of Death ; rlogin ; rootkit ; script kiddies

Smurf attack ; social engineering ; stack ; SYN flood
Trojan horse ; virus ; worms ; zombies
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Key Term Quiz:
Use terms from the Key Terms List to complete the sentences that follow. Don’t use
the same term more than once. Not all terms will be used.
a. ARP spoofing is what an attacker uses to forge (giả mạo) the _____________ of
the attacking computer.
b. __________________ is the process of overwhelming a computer system with
the intent of gaining elevated privileges.
c. When an attacker causes users to not be able to access system, applications, or
information, this is what is known as __________________.
d. Code with the intent of disrupting computer operations or destroying information
is known as __________________.
e. If you can access a remote computer system without authenticating with that
system, you are using __________________.
f. You would use a __________________ to cover up an instruction and gain
administrative access.
g. __________________ is a typical process used in testing a network address to
see if it is up and accepting requests and then increasing the packet size to the point that
it causes the target computer to crash.
h. Individuals who use scripts of others to target any computer system the encounter
are called __________________.
i. The __________________ controls what code the operating system will execute
next once the current code is completed.
j. Malicious code that appears to be useful program, but in reality is used to destroy
the computer system of collect information about the system, is known as a
__________________.
Multiple Choice Quiz:
1. Which of the following is the term most commonly associated with a person

who breaks into computer or networked systems?
a. Cracker
b. Cyberpunk
c. Hacker
d. User
2. Which is the most common motivation (động cơ) for hacker to break into
computers?
a. The challenge
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