Flashcards
363 - Security and Memes
Cards in this deck (97)
- 1What is 363?A GIANT FUCKIN MEME
- 2How do we know if two events A and B are Mutually Exclusive?if A ^ B is never true
- 3What does 1 and 0 Represent in Probability?1 = Always True
0 = Always False - 4How does a transposition cipher work?When letters are not changed but the order is.
- 5How does a substitution cipher work?When letters are changed but the order is not.
- 6Why is a shift cipher not secure?Plain text letters always map to the same Cipher letter.
- 7Method to break a substitution cipher?Most common/Frequent letters and letter combinations, eg:
"e" or "th" - 8What does mono-alphabetic mean?Each letter is always encoded to the same letter.
- 9What does poly-alphabetic mean?Shift cipher with different keys to different text positions.
- 10How can a Vigenere cipher be broken?Knowing the length of the key and using the most frequent letter method.
(Hard to do without knowing key length) - 11What is a symmetric cipher?Same key used to encrypt and decrypt.
- 12Goal of Security (in terms of encryption)1. Impossible for attacker to learn the key
2. Impossible to get plain text from cipher
3. Impossible to learn any character of plain from cipher - 13What does Perfect Secrecy mean?Observing the cipher text should not change the attackers knowledge about the distribution of the plain text
- 14What Encryption Mode is this?Electronic Code Book (ECB)
- 15What Encryption Mode is this?Cipher Block Chaining (CBC)
- 16What Encryption Mode is this?Counter (CTR)
- 17What is an "Adversary"?An entity that attacks, or is a threat to, a computing system.
- 18What is an "Attack"?An assault on system security that derives from an intelligent threat, that is a deliberate attempt to evade security services and violate a security policy
(cancer for slide copy) - 19What do Security Policies do?Define what is good/bad
- 20What are the 3 channel security concepts?Confidentiality
Integrity
Availability
(CIA) - 21What does Confidentiality mean? (channel security)Keeping data and resources hidden
- 22What does data Integrity mean? (channel security)Maintaining the consistency, accuracy, and trustworthiness of data over its entire life cycle. Data must not be changed in transit.
- 23What does origin integrity mean? (channel security)data cannot be altered by unauthorised people and comes from the correct source.
- 24What does availability mean? (channel security)Efficient transfer of information in the communication channel.
Enabling access to data and resources.
(copy off slide, oops) - 25What are the 2 Network Security concepts?Anonymity
Availability - 26What does Anonymity mean? (network security concepts)Untraceability
Unlinkability
Unobservability - 27What is a Threat?Set of circumstances that has the potential to cause loss or harm/potential violation to security
- 28What is a Vulnerability?Weakness in the system that can be exploited to cause loss or harm.
- 29What is Control or Countermeasure?A means to prevent vulnerability from being exploited.
- 30What does Security entail?Identifying Assets, Threats, Vulnerabilities and Countermeasures.
Assessing Risk. - 31What are the 4 classes of Threats?Disclosure
Deception
Disruption
Usurpation
(DUDD) - 32What is Repudiation?A false denial that an entity received some information.
- 33What is Falsification?Unauthorised change of information.
- 34What is Snooping/interception?Unauthorised interception of information via a network.
- 35What is Masquerading/Spoofing?An Impersonation of one entity by another.
- 36What is a Security Mechanism?Method, tool, or policy for enforcing a security policy?
- 37What could a Security Mechanism do?Prevent
Detect
Respond
Recover
(DRRP) - 38What should a Security Policy Lay out?Overall objectives
Principles
Underlying threat model - 39What is the Objective of the BLP Model? (Bell-LaPadula)Multi-Level Security
no personnel at lower levels should be able to access information at a higher level. - 40What is Path Traversal? (and an example)www.site.com/admin.php
easy to guess pages on a website.
can be done automatically. - 41How can we fix Path Traversal?Use different filenames.
Require Authentication for hidden pages.
Remove from google. - 42What is password cracking?Guessing the password of a user.
- 43How can we fix Password Cracking?Limit failed password attempts.
Human Checks (Captchas) - 44What is an Injection attack?Taking advantage of input,
making a website do somethings it not supposed to.
Command, SQL and XSS Injection - 45How can SQL Injection be Fixed?Sanitise inputs (Using escapes " \' ")
Prepared statements - 46What is XSS?Cross Site Scripting
Allows the user to inject client-side code into web-pages - 47What does XSS - Redirect do?Redirects user to malicious site
document.location=
"http://evil.com"; - 48How can we Fix XSS?Sanitization
- 49What is CSRF?Cross Site Request Forgery.
- 50The 4 Step example of CSRF1. Victim is logged into vulnerable site
2. Victim visits malicious page on attackers web site
3. Malicious content is delivered to victim
4. Victim is involuntarily sends a request to the vulnerable website - 51How can CSRF Be fixed?Use of On time tokens
- 522 Ways that websites can be blocked.DNS Blocking - saying the site user is looking for does no exist
IP Blocking - blocking connections through routers to website address. - 53What does Anonymous communication need in order to operate properly?More users. Bigger the crowd of users the more of the same everyone will look.
- 54How does onion routing work?Path to destination is chosen.
Message is encrypted with public keys of routers on path.
Each router on path removes outer layer - 55What are the 7 types of Malware?Virus
Backdoor
Tijan horse
Rootkit
Scareware
Adware
Worm - 56What is a Virus?a program that can infect other programs by modifying them to include a, possibly evolved version of itself
- 57What are the two types of VirusPolymorphic
(mutate while keeping the original algorithm intact. Whatever the fuck that means)
Metamorphic
(Change after each infection) - 58What is a Trojan?Malware that appears to perform a desirable function but in fact performs undisclosed malicious functions
- 59What is a rootkit?A root kit is a component that uses stealth to maintain a persistent and undetectable presence on the machine.
- 60What is a worm?Self-replicating computer program. Used a network and copies itself to other nodes without any user intervention.
- 61What is a botnet?Network of infected machines, under control from a botmaster used for carrying out DDoS and stealing information.
- 62What does APT Stand for?Advanced Persistent Threat
- 63What are the 4 steps in the Attack Life Cycle?Reconnaissance
Initial Compromise
Command and Control
Exfiltration - 64Explain Command and Control?How the malware talks to the malware owner.
- 65Two main typologies of Command and ControlCentralised
De-centralised - 66Advantages and Disadvantages to a Centralised botnet+ Easy to setup
+ Easy to maintain
- Single point of failure - 67Disadvantages of IRC For Command and Control- Easy to block
- Insecure
- Little Anonymity - 68Advantages and Disadvantages to Decentralised botnets+ Scalable
+Robust
+ No single point of failure
- Much more complext to set up - 69What is SteganographyThe art of information hiding
- 70Three ways to stop Command and ControlBlacklisting/Whitelisting
Sink-holing
Paritioning - 71How does sinkholing work?Force Command and Control traffic to controlled location
Keep botnet alive while removing attacker control - 72How does partitioning work?Partition the network that communication can not occur
(Protects against Decentralised C&C) - 73What does a Virus aim to infect?Executable
Interpreted File
Kernel
Service
MBR (wot)
Hypervisor (nice) - 74Two main approaches to detecting host-based malwareSignature-based detection
Heuristic-based detection
(Slides dont tell us what they are, £9000) - 75What are some Anti-virus detection methods?Virus Signature
Heuristic based detection
Checksum based detection - 76How does Virus Detection work by using Virus signature? What are the advantages and disadvantages of using this method?Find a "string" that can identify the virus
( strings in payload, specific calls )
+ Fast, Accurate
- Bad for new Viruses
- Easy to Evade - 77How does Heuristic based detection work? What are the advantages and disadvantages of using this method?Analyse program behaviour (network access, file open, attempt to delete file...)
+ Better for catching new malware
- Can still miss things and be evaded - 78How does Overwriting malware work?Overwrites targeted executable with malware
(self explanatory) - 79How does Prepending malware work?Runs on top of Infected host exe
- 80How does Cavity Malware work?Runs inside of the infected host exe
- 81How does Multi-Cavity malware work?Multiple instances of malware run within the infected host exe
- 82What do rootkits provide?Administrator level access to a computer or network
Uses low level layers of OS, bypasses security/anti virus - 83Detection mechanisms for detecting Command and Control...Clustering
Classifier
(fuck knows what that means) - 84What are the three associated domains in Access Control Lists?Owner
Group
Others - 85What are the three permissions in Access Control Lists?Read
Write
Execute - 86How does the Defence "Stack Canaries" work?Values placed around stack, which can be tested later
if stack is overwritten, values will change and can be detected - 87How does a TCP SYN Flood attack work?Attacker sends repeated SYN Messages to target
Target replies with SYN/ACK but attacker never responds
Target has to store half open connection - 88Goal of Bandwidth based attacksSend high bandwidth traffic to low bandwidth target
- 89What is the difference between Dos and DDoSAttacker uses more than one hose to carry out attack
- 90What is unintentional DDoSLegitimate reason drives lots of visitors to a service and overloads servers
(Black friday sales for all da cheapos) - 91How does a Reflected DoS attack work?Send forged request to large number of computers
Replies to spoofed source which is target - 92How does a Amplified Dos attack work?Responses are larger than request and are sent to spoofed source (target)
Attack volume is increased by large amount - 93How can DoS attacks be recognised?Sudden increase in traffic volume
attacker packet header info
IP Address, TTL Fields
spectral analysis - 94What makes DDoS Defence hard?Simplicity of performing a DDoS
Traffic Variety
IP Spoofing
High-volume traffic (per packet processing)
Short time span - 95How does Ingress filtering work?Routers check source IP is in leaf network pack it was received from
if not DROP it - 96Name and explain the three Degrees of CooperationAutonomous - Independent defence at the point of deployment
Cooperative - Perform better in join operation
Interdependent - cannot operate autonomously - 97—
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- Flashcards on 363 - Security and Memes, created by Alex Stout on 12/05/2018.
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- Alex Stout
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