CS6262 Final Exam Questions and
Answer
Random Scanning ANSWERS Each comprised computer probes random
addresses
Permutation Scanning ANSWERS All comprised computers share a common
psuedo-random permutation of the IP address space
Signpost Scanning ANSWERS Uses the communication patterns of the comprised
computer to find a new target
Hit List Scanning ANSWERS A portion of a list of targets is supplied to a
comprised computer
Subnet Spoofing ANSWERS Generate random addresses within a given address
space
Random Sppofing ANSWERS Generate 32-bit numbers and stamp packets with
them
Fixed Spoofing ANSWERS The spoofed address is the address of the target
Server Application ANSWERS The attack is targeted to a specific application on a
server
Network Access ANSWERS The attack is used to overload or crash the
communication mechanism of a network
Infrastructure ANSWERS The motivation of this attack is a crucial service of a
global internet operation, for example core router
DoS Bug (Amplification Attack) ANSWERS Design flaw allowing one machine to
disrupt a service
DoS Flood (Amplification Attack) ANSWERS Command botnets to generate flood
of requests
UDP-based NTP ANSWERS -Particularly vulnerable to amplification attacks
-Small command can generate a large response
-Vulnerable to source IP spoofing
, -Difficult to ensure computers only communicate with legitimate NTP servers
IP Header Format ANSWERS -Connectionless
-Unreliable
-No authentication
SYN Flood ANSWERS A type of DoS where an attacker sends a large amount of
SYN request packets to a server in an attempt to deny service.
SYN Flood Mitigations ANSWERS Syn Cookies - remove state from server, but
incur performance overhead
Crowdturfers ANSWERS - Crowdsource to create, verify, and manage fake
accounts
- Solve CAPTCHAs
Penetration Testing ANSWERS Footprinting, Scanning, Enumeration, Gaining
Access, Escalating Privileged, Pilfering (steal data), Covering Tracks, Creating
Backdoors
NS Record ANSWERS Points to other server
A Record ANSWERS Contains IP Address
MX ANSWERS Address in charge of handling email
TXT ANSWERS Generic text; distribute site public keys
DNS vulnerabilities ANSWERS - Users/hosts trust the host-address mapping
provided by DNS
- Interception of requests or compromise of DNS servers
- Few use DNSsec
- Cache poisining
Cache Poisoning ANSWERS Corrupting an Internet server's DNS table by
replacing an Internet address with that of another, rogue address. When a Web user
seeks the page with that address, the request is redirected by the rogue entry in the
table to a different address. At that point, a worm, spyware, Web browser hijacking
program, or other malware can be downloaded to the user's computer from the rogue
location.
DNSsec ANSWERS - Authenticity of DNS answer origin
- Integrity of reply
- Authenticity of denial of existence
- Uses public key crypto to sign responses
Answer
Random Scanning ANSWERS Each comprised computer probes random
addresses
Permutation Scanning ANSWERS All comprised computers share a common
psuedo-random permutation of the IP address space
Signpost Scanning ANSWERS Uses the communication patterns of the comprised
computer to find a new target
Hit List Scanning ANSWERS A portion of a list of targets is supplied to a
comprised computer
Subnet Spoofing ANSWERS Generate random addresses within a given address
space
Random Sppofing ANSWERS Generate 32-bit numbers and stamp packets with
them
Fixed Spoofing ANSWERS The spoofed address is the address of the target
Server Application ANSWERS The attack is targeted to a specific application on a
server
Network Access ANSWERS The attack is used to overload or crash the
communication mechanism of a network
Infrastructure ANSWERS The motivation of this attack is a crucial service of a
global internet operation, for example core router
DoS Bug (Amplification Attack) ANSWERS Design flaw allowing one machine to
disrupt a service
DoS Flood (Amplification Attack) ANSWERS Command botnets to generate flood
of requests
UDP-based NTP ANSWERS -Particularly vulnerable to amplification attacks
-Small command can generate a large response
-Vulnerable to source IP spoofing
, -Difficult to ensure computers only communicate with legitimate NTP servers
IP Header Format ANSWERS -Connectionless
-Unreliable
-No authentication
SYN Flood ANSWERS A type of DoS where an attacker sends a large amount of
SYN request packets to a server in an attempt to deny service.
SYN Flood Mitigations ANSWERS Syn Cookies - remove state from server, but
incur performance overhead
Crowdturfers ANSWERS - Crowdsource to create, verify, and manage fake
accounts
- Solve CAPTCHAs
Penetration Testing ANSWERS Footprinting, Scanning, Enumeration, Gaining
Access, Escalating Privileged, Pilfering (steal data), Covering Tracks, Creating
Backdoors
NS Record ANSWERS Points to other server
A Record ANSWERS Contains IP Address
MX ANSWERS Address in charge of handling email
TXT ANSWERS Generic text; distribute site public keys
DNS vulnerabilities ANSWERS - Users/hosts trust the host-address mapping
provided by DNS
- Interception of requests or compromise of DNS servers
- Few use DNSsec
- Cache poisining
Cache Poisoning ANSWERS Corrupting an Internet server's DNS table by
replacing an Internet address with that of another, rogue address. When a Web user
seeks the page with that address, the request is redirected by the rogue entry in the
table to a different address. At that point, a worm, spyware, Web browser hijacking
program, or other malware can be downloaded to the user's computer from the rogue
location.
DNSsec ANSWERS - Authenticity of DNS answer origin
- Integrity of reply
- Authenticity of denial of existence
- Uses public key crypto to sign responses
