InfoSec Flashcards
What is a security plan?
A plan that identifies and organizes the security activities for a system/organization
What does a security plan do?
Describes the current situation and highlights the improvement
It is an official record of current security practices and a blueprint for orderly change to improve those practices
What three essential questions should a security policy answer?
Who should be allowed access?
To what system and organizational resources should access be allowed?
What types of access should each user be allowed for each resource?
What should a security policy specify?
- The organization’s security goals
- Where the responsibility for security lies
- The organization’s commitment to security
How should a security policy be written?
Not too long, complex, detailed, and fast and easy to read
What does “current security status” mean?
- An understanding of the current vulnerabilities.
- Defines the limits of responsibility for the security
What is risk analysis?
A systematic investigation of the system, its environment, and what might go wrong
And then forms the basis for describing the current security state
What’s the meaning of security requirements?
Security requirements are functional or performance demands placed on a system to ensure a desired level of security
What is the characteristics of good security requirements?
- Correctness: Are the requirements understandable? Are they stated without error?
- Consistency: Are there any conflicting or ambiguous requirements?
- Completeness: Are all possible situations addressed by the requirements?
- Realism: Is it possible to implement what the requirements mandate?
- Need: Are the requirements unnecessarily restrictive?
- Verifiability: Can tests be written to demonstrate conclusively and objectively that the requirements have been met?
- Traceability: Can each requirement be traced to the functions and data related to it so that changes in a requirement can lead to easy reevaluation?
What’s the meaning behind accountability/responsibility for implementation
A section of the security plan that will identify which people (roles) are responsible for implementing security requirements
What is the common roles in a security plan?
- Users –Regardless of if they are responsible for the security of their own machines, they have some responsibility
- Owners –Product/process/system/…
- Managers - May be responsible for seeing that the people they supervise implement security measures, and can also be legally responsible
- Administrators –Network/system/security/database/…
- Information officers - May be responsible for overseeing the creation and use of data; these officers may also be responsible for the retention and proper disposal of data
- Personnel staff members - May be responsible for security involving employees, e.g., screening employees, handling terminations, arranging security training programs
What is a timetable?
A timetable means of how and when the elements in it will be performed must be included
What is a plan maintenance?
A plan that specify the order which controls are to be implemented.
What must be included in a plan maintenance?
- New equipment will be acquired
- New connectivity requested
- New threats identified…
- The plan must include procedures for change and growth
- The plan must include a schedule for periodic review
Why does security planning need team members and commitment?
Security planning touches every aspect of an organization and therefore requires participation well beyond the security group
What three groups must contribute to making a security plan if you want it to succeed?
- Management
- The planning team
- Those affected by the security
What is a business continuity plan?
A (business) continuity plan documents how a business will continue to function during or after a computer security incident
What does a business continuity plan address?
- Catastrophic situations, in which all or a major part of a computing capability is suddenly unavailable
- Long duration, in which the outage is expected to last for so long that business will suffer
What does a business continuity plan assess?
- What are the essential assets?
- What could disrupt the use of these assets?
What us the goal of a incident response?
Be able to handle the current security incident without direct regard for the business issues
What is a security incident response plan?
It tells the staff how to deal with a security incident
A incident response plan should include?
- Define what constitutes an incident
- Identify who is responsible for taking charge of the situation
- Describe the plan of action
What is ISO/IEC 27005 about?
Information security risk management (ISRM)
What is ISO 31000 about?
(general) Risk Management (RM) (principles and guidelines)
What ISO has several terms according to it?
ISO 27000
What does risk mean?
Effect of uncertainty on objectives
What is risk management?
Coordinated activities to direct and control an organization with regard to risk
What is risk management process?
Systematic application of management policies, procedures and practices to the activities of communicating, consulting, establishing the context and identifying, analyzing, evaluating, treating, monitoring and reviewing risk
What is risk assessment?
Overall process of risk identification, risk analysis and risk evaluation
What is risk identification?
process of finding, recognizing and describing risks
What is risk evaluation?
process of comparing the results of risk analysis with risk criteria to determine whether the risk and/or its magnitude is acceptable or tolerable
What does “Level of risk” mean?
magnitude of a risk expressed in terms of the combination of consequences and their likelihood
What does “residual risk” mean?
risk remaining after risk treatment
What does risk treatment mean
Process to modify risk
What does vulnerability mean?
Weakness of an asses or control that can be exploited by one or more threats
What does threat mean?
potential cause of an unwanted incident, which may result in harm to a system or organization
What is ISO?
the process to comprehend the nature of risk and to determine the level of risk
What is the characteristics of a risk?
- Associated loss (also known as a risk impact)
- Likelihood of occurring
- The degree to which we can change the outcome (risk control)
Strategies for dealing with risk?
- Avoid the risk by changing requirements for security or other system characteristics
- Transfer the risk by allocating the risk to other systems, people, organizations, or assets or by buying insurance to cover any financial loss should the risk become a reality
- Assume the risk by accepting it, controlling it with available resources, and preparing to deal with the loss if it occurs
What’s the steps of a risk analysis?
- Identify assets
- Determine vulnerabilities
- Estimate the likelihood of exploitation
- Compute expected annual loss
- Survey applicable controls and their costs
- Project annual savings of control
What is the pros with risk analysis?
- Improve awareness
- Relate security mission to
management objectives - Identify assets, vulnerabilities, and
controls - Improve basis for decisions
- Justify expenditures for security
What is the cons of risk analysis?
- False sense of precision and confidence
- Hard to perform
- Have a tendency to be filed and promptly forgotten
- Lack of accuracy
What is management systems?
A management system is a “set of interrelated or interacting elements of an organization to establish policies and objectives and processes to achieve those objectives” (ISO/IEC 27000:2014)
What is the PDCA/continual improvement?
Also known as the demming cycle
* Used when:
* Starting from scratch, or when
* Improving or when, or when
* Performing a task
- Also, on different levels
- Strategic –Organization as a whole, policy,
long-term… - Tactical –Implements the decisions…
- Operational –Day-to-day operations…
What is cyber terrorism?
The use of computers to launch a terrorist attack
What can cyber terrorism cause?
- Significant economic damage
- Disruptions to communications
- Disruptions in supply lines
- Disruptions in national infrastructure
What is an Economic attack?
An attack that causes economic damage.
- Lost files and records
- Destroyed data
- Stolen credit cards
- Money stolen
- Time spent cleaning up
What is cryptanalysis?
the study of methods for breaking ciphertext
What is cryptography?
the use and practice of cryptographic techniques
What is cryptology?
the study of both cryptography and cryptanalysis
What is plaintext/cleartext, P?
The original form a message
What is ciphertext/cyphertext, C?
encrypted version of a message
What is a Cipher?
a pair of cryptographic algorithms, e.g., a mathematical function used for encryption and one for decryption
The character for a plaintext message?
P
The character for a ciphertext?
C
What is the cryptosystem in formal notation?
P = D(E(P))
What is an encryption algorithm?
A set of rules of how to encrypt plaintext and how to decrypt the ciphertext
The ciphertext for cipher system with a key?
C = E(K, P)
What is a symmetric cryptosystem?
- Encryption and decryption keys are the same
- Provide a two-way channel to their users
- If the key is kept secret for a pair - the system also provides authentication proof
- If the secret key is compromised, the adversary can decrypt all traffic and produce fake messages
What is an Asymmetric cryptosytem?
*One key for encryption and another key for decryption
* Keys come in pairs
* A decryption key, KD, inverts the encryption of key KE so that:
* P = D(KD, E(KE,P))
* Also called public key
What is a Stream cipher?
- Each bit/byte of the data stream is encrypted separately (low diffusion)
- Fast and encryption can take place as soon as data is read
- If errors occur, only bit/byte is affected
- Susceptible to malicious insertions and modifications
What is a block cipher?
- Encrypts a group of plaintext symbols as a single block (typically 64, 128, 256 bits or
more) (high diffusion) - Slower process, the last block needs to be padded, and an error affects more bytes
- Impossible to insert a single symbol into one block
What is The Data Encryption Standard (DES)?
- Symmetric block cipher
- Encryption and decryption algorithms are public but the design principles are classified
- Used fixed 56 bits (short) key
- Is considered insecure and was deprecated in 2017
What is The Advanced Encryption Standard (AES)?
- A replacement for DES
- Symmetric, block cipher (128) bits
- Three different key lengths: 128, 192, and 256 bits
What is the de-facto encryption standard today?
AES
- Used in e.g., WPA2, IPsec, WhatsApp, Telegram… and in hardware such as Intel & AMD processors
What is Rivest-Shamir-Adelman (RSA)?
- Asymmetric block cipher
- Public key system (i.e., one private and one public key)
- Long keys (1024-4096 bits)
- Slow algorithm
What is the Diffie-Hellman key exchange protocol?
A way in which a public channel can be used to create a confidential shared key
How does the Diffie-Hellman key exchange work?
- First agree on an arbitrary staring key
- Then pick a private key
- Mix the (public) starting key with the secret key
- Exchange the keys with each other
- Mix the other shared key with their own secret key
What is error detecting codes?
A fast and reliable way of finding out if an error in a transmission have happened
Name some simple error detecting codes?
- Parity checks
- Cyclic redundancy checks
Name some cryptographic error detecting codes?
- One-way hash functions
- Cryptographic checksums
- Digital signatures
What’s in Shannon’s characteristics of good ciphers?
- The amount of secrecy needed should determine the amount of labor appropriate for the encryption and decryption
- The set of keys and the enciphering algorithm should be free from complexity
- The implementation of the process should be as simple as possible
- Errors in ciphering should not propagate and cause corruption of further information in the message
- The size of the enciphered text should be no larger than the text of the original message
What is Interception?
Unauthorized viewing
CIA: Confidentiality
Network security examples: Eavesdropping or wiretapping
What is Modification?
Unauthorized change
CIA: Integrity
Network security examples: Integrity failures - insertion
What is Fabrication?
Unauthorized creation
CIA: Integrity
Network security examples: Integrity failures - replay
What is Interruption?
Preventing authorized access
CIA: Availability
Network security examples: DoS/DDoS
What vulnerabilities is there in Wi-Fi?
- It’s prone to eavesdropping
- Shared media = easy insertion and easy disruption (DoS)
- Protocols such as WEP and WPA
What is the standard Wireless protocol?
WPA2/802.11i
What is a policy?
- A security policy is a document that defines how an organization deals with some
aspect of security. - There can be policies regarding end user behavior, IT response to incidents, or
policies for specific issues and incidents.
What does CYOD mean?
The company lists acceptable devices (that is, those that meet company security requirements) and allows each employee to choose his or her own device.
What is COPE?
The company owns and provides the equipment. This clearly offers the most security, but also comes at the highest cost.
What does “personal” mean in WPA and WPA2?
Home and small office use
- Using a pre-shared key
- No authentication server
- A shared key is a security issue (e.g., guessing attacks)
What does “Enterprise” mean in WPA and WPA2?
Bigger organizations
- Uses authentication server
- No pre-shared key
- Use IEEE 802.1X (so the access point become the authenticator), mutual authentication (i.e., no man-in-the-middle)
What is segmentation?
Dividing a network into smaller segments.
What is important for network security countermeasures?
- System architecture
- Segmentation
- DMZ
- Redundancy
- Encryption
What is a Virtual Private Network (VPN)?
I provides a way to the Internet. It creates a virtual connection between a remote user and the central location.
What two approaches are it to VPN?
- Remote access - one fixed side (What you get if you buy a VPN Service)
- Site-to-site - two fixed sites
Why use a VPN?
Is cheap, secure, scalable, and flexible
What is a firewall?
A device that filters all traffic between a protected or “inside” network and less trustworthy or “outside” network
Firewalls implement security policies or rule-sets that determine what traffic can or cannot pass through
What is a firewall an example of?
A reference monitor
* Always invoked (cannot be circumvented)
* Tamperproof
* Small and simple enough for rigorous analysis
What is a demilitarized zone?
- A perimeter network or screened subnet
- Physical or logical subnetwork
- DMZ is a form of network architecture
- Services dedicated to outside use separated
- The idea is that intrusion of DMZ hosts lead
to only limited damage to the internal hosts
What is a Intrusion Detection System (IDS)?
It monitors activity malicious or suspicious events
What may a IDS do?
- Monitor user and system activity
- Audit system configurations for vulnerabilities and
misconfigurations - Assess the integrity of critical system and data files
- Recognize known attack patterns in system activity
- Identify abnormal activity through statistical analysis
- Manage audit trails and highlight policy violations
- Install and operate traps to record information about
intruders
What is the goal of an IDS?
- Ideally, an IDS should be fast, simple, and accurate while at the same time being complete
- It should detect all attacks with little performance penalty
What is an IDS detection methods?
Signature-based
* Monitor and compare against patterns (signatures)
* Signatures can be e.g., series of TCP SYN packets sent to many different ports in succession and at times close to one another
* Cannot detect new attacks (zero-day)
* Modification of existing attacks to evade detection
* Rely on statistical analysis
Heuristic
* Anomaly-based, based on a model of acceptable behavior and flag exceptions to that model
* Looks for behavior that is out of the ordinary
* Could be based on current traffic behavior or user behavior
What is the Scope of an IDS?
Network-based IDS (NIDS)
* Stand-alone device
* Placed at a strategic point in the network, monitoring traffic to and from all devices on the network
Host-based IDS (HIDS)
* Installed on individual hosts or devices on the network
What is the location of an IDS?
Front end
* Looks at traffic as it enters the network
* Can spend a long time analyzing
* Can filter before entering network (like a firewall)
* Easier to spot from the outside (and possibly to circumvent or attack)
* Not checking the internal network
Internal
* Monitors traffic within the network
* Less exposed
* Handle both internal and external traffic
What is the Capability of IDS?
- Passive –sound the alarm
- Active, that’s when it become IPS
How does a IPS respond to an alarm?
- Monitor and collect data
- Increase data collection during event e.g., record all traffic from a given source for future analysis
- Watch the intruder - see accessed resources
- Protect
- Act to reduce exposure, e.g., by increasing access controls
- Making assets unavailable
- Visible
- Signal an alert to other protection components
- Call a human
What is capacity planning?
- Know what cause spikes in traffic
- Plan for them
What is load balancing?
- Use more machines
- Buy more cloud capacity
What is network tuning?
- Adjusting the number of segments, machines, uplinks…
- Rate limiting - countermeasure that reduces the impact of an attack by limiting capacity to a host/network
What is shunning?
Reducing service given to traffic from certain address ranges
What is blacklisting?
Blocking all traffic to/from a specific host
What is sinkholing?
Incoming traffic is analyzed, and bad traffic rejected
What is a honeypot?
A virtual machine meant to lure an attacker into an environment that can be both controlled and monitored
What is simplicity of design in a OS?
OSs are inherently complex, and any unnecessary complexity only makes them harder to understand and secure
What is layered design?
- At least four levels: hardware, kernel, OS, and user
- Enables layered trust
What is layered trust?
- Layering is both a way to keep a design logical and understandable and a way to limit risk
- Very tight access controls on critical OS functions, fewer access controls on important noncritical functions, and few if any access controls on functions that aren’t important to the OS
What is a kernel?
- A kernel is the part of the OS that performs the lowest-level functions
- Synchronization, inter-process communication, interrupt handling…
What is a security kernel?
- A security kernel is responsible for enforcing the security mechanisms of the entire OS
- Typically contained within the kernel
What is kernel-mode?
Kernel-mode - executing code has complete and unrestricted access to the underlying hardware and memory
What is User-mode?
User-mode - executing code has no direct access to hardware or reference memory
What does execution mean?
- The OS should be responsible for executing processes
- When a user-mode application is executed, the OS creates a process for the application
What is a reference monitor?
- A reference monitor mediates access by subjects to objects (e.g., to let a user read a file)
- An easy way of implementing access control
A reference monitor must be?
- Tamperproof
- Unbypassable
- Analyzable
What is access control?
- Authentication is verifying the identity of a user or a host
- Authorization is permitting or restricting access to the information based on the type of users and their roles
- Accountability identifies what a user did (auditing)
- Access control is often performed by the OS
What is the requirements of access control?
- Need a mechanism to authenticate
- Least privilege - minimum authorization to do its work
- Separation of duty - should divide steps in a system function among different individuals
- Administrative policies - who can add, delete, modify rules
- Closed vs. open policies
- Closed = disallowed unless explicitly allowed
- Open = allowed unless explicitly disallowed
What is the access control elements?
- Subject
- An entity that can access objects (often the human user)
- Objects
- Are things on which an action can be performed
- Access modes
- Any controllable actions of subjects on objects
What is Discretionary access control (DAC)?
Access control model based on the identity of the user
* The owner decides who is allowed to access the object
and what privileges they have
* Rights can be delegated at users’ discretion
* Most common model
- Often provided using an access control matrix
- Access control lists (decomposed by column)
- Capability tickets (decomposed by row)
What is Role-based access control (RBAC)?
- Controls based on a subject’s (user’s or program’s) role, not their identity
- Subject’s rights can change depending on their current role
- access is controlled at the system level, outside of the user’s control
- Used in, e.g., Microsoft Azure
What does reconnaissance mean?
The hacker research their target
What does reconnaissance (passive) mean?
- Before an attack is executed the hacker attempt to find out information about the target system
What does Reconnaissance (Active) mean?
Port scanning (Nmap) Scans to see which ports are open
- Ping scan
- Connect scan
- SYN scan
- FIN scan
What is a Ping scan?
A ping sweep (also known as an ICMP sweep) is a basic network scanning technique used to determine which of a range of IP addresses map to live hosts (computers).
What is a connect scan?
- Complete connection is executed
with the destination device. - Most likely to be detected.
What is a SYN scan?
- Stealthy scan
- Also called half-open scan
You send a SYN packet but you
never respond to the SYN/ACK
What is an SQL attack?
You enter SQL commands into login forms to trick the server into executing those commands.
- The most common attack.
- The most common purpose is to force the server to log the attacker on.
What is Bluesnarfing?
Unauthorized access of information from a Bluetooth device
What is Blue jacking?
Using another blue tooth device within range and sending messages to the target
What is Bluebugging?
Accesses and uses all phone features
What is Pod slurping?
Using a device such as an iPod to steal confidential data by directly plugging it into a computer where the data are held
Why does a buffer overflow occur?
Data is written beyond the space allocated
* Inputs expected to go into regions of memory allocated for data end up in memory holding executable code
What is Malware?
Software planted by an agent with malicious intent to cause unanticipated or undesired effects
What is a Virus?
A program that can replicate itself and pass on malicious code to other non-malicious programs by modifying them
What is a Worm?
A program that spreads copies of itself through a network
What is a Trojan Horse?
A application/software that looks legit but contains code that, in addition to its stated effect, has a second, nonobvious, malicious effect
What is a Rabbit?
Code that replicates itself without limit to exhaust resources
What is a Logic Bomb?
Code that triggers when a predetermined condition occurs
What is a Time Bomb?
Code that triggers action when a predetermined time occurs
What is a Dropper?
Transfer agent code only to drop other malicious code, such as virus or Trojan horse
What is Hostile mobile code agent?
Code communicated semi-autonomously by programs transmitted through the web
What is a cross-site script attack?
- Tricking a client or server into executing scripted code by including the code in data inputs
- An attacker can gain elevated access privileges to sensitive content, cookies, and other information maintained by the browser
What is a RAT (remote access Trojan)?
Trojan horse that, once planted, gives access from remote location
What is Spyware?
Program that intercepts and covertly communicates data on the user or user’s activity
What is a bot?
Semi-autonomous agent, under control of a (usually remote) controller or “herder”; not necessarily malicious
What is a Zombie?
Code or entire computer under control of a (usually remote) program
What is a Browser hijacker?
Code that changes browser settings, disallows access to certain sites, or redirects browser to other
What is a Rootkit?
A collection of tools that a hacker uses to mask their intrusion and obtain admin-level access to a computer or network.
What is trapdoor or backdoor?
Code feature that allows unauthorized access to a machine or program; bypasses normal access control and authentication
What is a tool or toolkit?
Program containing a set of tests for vulnerabilities; not dangerous itself, but each successful test identifies a vulnerable host that can be attacked
What is Scareware?
Not code; false warning of malicious code attack
What kind of harm can malicious code do?
Harm to users and systems:
* Sending emails to user contacts
* Deleting or encrypting files
* Modifying system information, such as the Windows registry
* Stealing sensitive information
* Attaching to critical system files
* Hide copies of malware in multiple complementary locations
What are some countermeasures for users to protect them from Malware?
- Use software acquired from reliable sources
- Test software in an isolated environment
- Only open attachments when you know them to be safe
- Treat every website as potentially harmful
- Create and maintain backups
What are some countermeasures that doesn’t work against Malware?
Penetrate-and-patch
* Search after flaws and then fix them
* Fails because it is normally hurried, misses the context of the fault, and focuses on one failure, not the complete system
Security by obscurity (or Security through obscurity)
* Things meant to stay hidden seldom do
* Security should not depend on the secrecy of the implementation or its components
A perfect good-bad code separator
* Impossible to separate good programs from bad
How does virus scanners work?
Virus scanners look for signs of malicious code infection using signatures in program files and memory
Detection mechanisms:
* Known string patterns in files or memory
* Execution patterns
* Storage patterns
What is a Denial-of-Service Attacks?
A way to prevent legitimate access to a system, by flooding the system with so many false connection requests that the system cannot respond to legitimate requests
What is DHCP Starvation?
If enough requests flooded a network, the attacker could completely exhaust the address space allocated by the DHCP servers for an indefinite period of time
What are some DoS weaknesses?
- The flood must be sustained.
- When machines are disinfected, the attack stops.
- Hacker’s own machine are at risk of discovery
How does a SYN Attack/Flood work?
- The client sends a SYN.
- Server responds with SYN+ACK
The client should now respond with an ACK, but through non –responsiveness and continues sending of a SYN from other clients the server ends up in a busy state.
How does a UDP Flood work?
- Connectionless protocol.
- UDP packet delivery to random port.
- ICMP response “destination unreachable”.
- Enough packets overloads system.
What is Low Orbit Ion Cannon? (LOIC)
- A common tool for DoS attacks
- Requires the user to put in the target URL or IP address and then begin the attack
What is XOIC?
- XOIC is another DoS attacking tool.
- Performs a DoS attack on any server with an IP address, a user-selected port, and a user-selected protocol.
How do you protect yourself against Smurf attacks?
- Guard against Trojans.
- Have adequate Anti Virus software.
- Utilize proxy servers..
What is Ping of Death?
- A ping of death is a type of attack on a computer system that involves sending a malformed or otherwise malicious ping to a computer.
- A ping packet that is oversized.
- Some computer systems were never designed to properly handle a ping packet larger than the
maximum packet.
What is a Man-in-the-Browser?
- Malicious code in browser/add-ons
- The key point is that it enters before
encryption, and if something is
inserted, it is also encrypted
What is a Keystroke logger?
- Hardware or software that records all keystrokes
- It may be a small dongle plugged into a USB port or can masquerade as a keyboard
- It may also be installed as malware
What is Page-in-the-Middle
- The user is directed to a different page than believed or intended
- Similar to man-in-the-browser
- Here a new page is displayed. The man-in-the-browser is only in the background
What is a download substitution?
- The attacker creates a page with seemingly harmless and desirable programs for download
- Instead of, or in addition to, the intended functionality, the user installs malware
- This is a very common technique for spyware
- The user does not know what is installed after they click YES.
What is clickjacking?
- A way of tricking user into providing desired input, like personal information
What is Drive-by download?
Code is downloaded, installed, and executed on a computer without the user’s knowledge.
What is SQL injection?
Injecting SQL code into an exchange between an application and its database server
What is Phishing?
A message that tries to trick a victim into providing private information or taking some other unsafe action
What is Spear phishing?
A more personalized attack to a particular recipient or set of recipients
What is Whaling?
Attacks directed at high-profile targets such as CEO:s…
