Review - CS6262 Final Exam QUESTIONS WITH WELL VERIFIED
ANSWERS
Random Scanning - answer☑️✔️..Each comprised computer probes random addresses
Permutation Scanning - answer☑️✔️..All comprised computers share a common psuedo-
random permutation of the IP address space
Signpost Scanning - answer☑️✔️..Uses the communication patterns of the comprised
computer to find a new target
Hit List Scanning - answer☑️✔️..A portion of a list of targets is supplied to a comprised
computer
Subnet Spoofing - answer☑️✔️..Generate random addresses within a given address space
Random Spoofing - answer☑️✔️..Generate 32-bit numbers and stamp packets with them
Fixed Spoofing - answer☑️✔️..The spoofed address is the address of the target
Server Application - answer☑️✔️..The attack is targeted to a specific application on a server
Network Access - answer☑️✔️..The attack is used to overload or crash the communication
mechanism of a network
Infrastructure - answer☑️✔️..The motivation of this attack is a crucial service of a global
internet operation, for example core router
,DoS Bug (Amplification Attack) - answer☑️✔️..Design flaw allowing one machine to disrupt a
service
DoS Flood (Amplification Attack) - answer☑️✔️..Command botnets to generate flood of
requests
UDP-based NTP - answer☑️✔️..-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 - answer☑️✔️..-Connectionless
-Unreliable
-No authentication
SYN Flood - answer☑️✔️..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 - answer☑️✔️..Syn Cookies - remove state from server, but incur
performance overhead
Crowdturfers - answer☑️✔️..- Crowdsource to create, verify, and manage fake accounts
- Solve CAPTCHAs
Penetration Testing - answer☑️✔️..Footprinting, Scanning, Enumeration, Gaining Access,
Escalating Privileged, Pilfering (steal data), Covering Tracks, Creating Backdoors
,NS Record - answer☑️✔️..Points to other server
A Record - answer☑️✔️..Contains IP Address
MX - answer☑️✔️..Address in charge of handling email
TXT - answer☑️✔️..Generic text; distribute site public keys
DNS vulnerabilities - answer☑️✔️..- 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 - answer☑️✔️..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 - answer☑️✔️..- Authenticity of DNS answer origin
- Integrity of reply
- Authenticity of denial of existence
- Uses public key crypto to sign responses
TCP Problems - answer☑️✔️..- Network packets pass untrusted hosts
, - TCP state easily obtained by eavesdropping
- IP info not protected
Open Shortest Path First (OSPF) - answer☑️✔️..An interior gateway routing protocol
developed for IP networks based on the shortest path first or link-state algorithm.
Looks for the lowest cost path within nodes.
Border Gateway Protocol (BGP) - answer☑️✔️..A core routing protocol that bases routing
decisions on the network path and rules.
Protocol designed to exchange routing and reachability information among autonomous
systems (AS).
Botminer - answer☑️✔️..- Botnet can have different infection life cycles and they can change
protocols and structure of the command-and-control
- C-Plane monitor for C&C traffic
- A-Plane monitor malicious instances
Defense in Depth - answer☑️✔️..Prevention, Detection, Survival
Shamir's Scheme Simulation - answer☑️✔️..- Add or delete shares without affecting others
- Easy to create new shares without changing secret
- Easy to create hierarchical schemes
- Information theoretic security
ANSWERS
Random Scanning - answer☑️✔️..Each comprised computer probes random addresses
Permutation Scanning - answer☑️✔️..All comprised computers share a common psuedo-
random permutation of the IP address space
Signpost Scanning - answer☑️✔️..Uses the communication patterns of the comprised
computer to find a new target
Hit List Scanning - answer☑️✔️..A portion of a list of targets is supplied to a comprised
computer
Subnet Spoofing - answer☑️✔️..Generate random addresses within a given address space
Random Spoofing - answer☑️✔️..Generate 32-bit numbers and stamp packets with them
Fixed Spoofing - answer☑️✔️..The spoofed address is the address of the target
Server Application - answer☑️✔️..The attack is targeted to a specific application on a server
Network Access - answer☑️✔️..The attack is used to overload or crash the communication
mechanism of a network
Infrastructure - answer☑️✔️..The motivation of this attack is a crucial service of a global
internet operation, for example core router
,DoS Bug (Amplification Attack) - answer☑️✔️..Design flaw allowing one machine to disrupt a
service
DoS Flood (Amplification Attack) - answer☑️✔️..Command botnets to generate flood of
requests
UDP-based NTP - answer☑️✔️..-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 - answer☑️✔️..-Connectionless
-Unreliable
-No authentication
SYN Flood - answer☑️✔️..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 - answer☑️✔️..Syn Cookies - remove state from server, but incur
performance overhead
Crowdturfers - answer☑️✔️..- Crowdsource to create, verify, and manage fake accounts
- Solve CAPTCHAs
Penetration Testing - answer☑️✔️..Footprinting, Scanning, Enumeration, Gaining Access,
Escalating Privileged, Pilfering (steal data), Covering Tracks, Creating Backdoors
,NS Record - answer☑️✔️..Points to other server
A Record - answer☑️✔️..Contains IP Address
MX - answer☑️✔️..Address in charge of handling email
TXT - answer☑️✔️..Generic text; distribute site public keys
DNS vulnerabilities - answer☑️✔️..- 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 - answer☑️✔️..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 - answer☑️✔️..- Authenticity of DNS answer origin
- Integrity of reply
- Authenticity of denial of existence
- Uses public key crypto to sign responses
TCP Problems - answer☑️✔️..- Network packets pass untrusted hosts
, - TCP state easily obtained by eavesdropping
- IP info not protected
Open Shortest Path First (OSPF) - answer☑️✔️..An interior gateway routing protocol
developed for IP networks based on the shortest path first or link-state algorithm.
Looks for the lowest cost path within nodes.
Border Gateway Protocol (BGP) - answer☑️✔️..A core routing protocol that bases routing
decisions on the network path and rules.
Protocol designed to exchange routing and reachability information among autonomous
systems (AS).
Botminer - answer☑️✔️..- Botnet can have different infection life cycles and they can change
protocols and structure of the command-and-control
- C-Plane monitor for C&C traffic
- A-Plane monitor malicious instances
Defense in Depth - answer☑️✔️..Prevention, Detection, Survival
Shamir's Scheme Simulation - answer☑️✔️..- Add or delete shares without affecting others
- Easy to create new shares without changing secret
- Easy to create hierarchical schemes
- Information theoretic security
