Final Exam Review, Fall 2018

I compiled these by going through the slides and basically outline-formatting them. This is a structure to help guide you – it is not an all-inclusive guide.

If I make substantial updates to this guide, I will write about it on the #final_guide_changelog slack channel

Let’s use the #final_exam_prep slack channel for q & a about things on this guide.

Introduction to the class

Kinds of Attackers
- Rogue hackers
- Organized Crime
  - Credit Card fraud
    - Move to chip
  - Bank theft
    - ATMs
    - Swift network
- Insider threat
  - Edward snowden
  - Rogue DEA agents
- Nation states
  - China attacking RSA
  - North korea
  - Russia attacking Ukraine, notpetya
  - US and Israel attacking Iran, Stuxnet

Threat Modeling

Cheating exercise
Eliminating versus mitigating risk. Security = managing acceptable level of risk. Not a binary property
Definitions:
- risk = impact x probability
- Risk = asset x vulnerability x threat
X-wing death star attack
Security cards:
- Human impact
- Adversary motivations
- Adversary resources
- Adversary methods
Security is a mindset

Cryptography – Symmetric Encryption and Hashing

Cryptography provides these fundamental security needs:
- Confidentiality
- Integrity
- Authenticity
- Non-repudiation
Cryptographic primitives for each of the above provisions: (See here)
History of crypto
- Domain of spies and military
  - Telegram
  - War radio communications
  - Classified as a munition
- Clinton crypto wars, 1990s, clipper-chip, encryption declassified
- Apple vs fbi
  - Which attacker did apple leave out of their phone-encryption threat model
Definitions
- taxonomy:
  - Cryptology
    - Cryptanalysis
    - Cryptography
      - Substitution
        
        Code
        
        cipher
      - transposition
  - Steganography
- Plaintext vs ciphertext
Building blocks: * Transposition * E.g., scytale * Substitution * ciphers: * Caesar cipher * Vignere cipher * Attacks * Brute force * Frequency analysis
Enigma machine
Claude shannon – substitution and transposition, sufficiently combined, yield encrypted data that is indistinguishable from random data
Kerckhoff’s principle: the secret is in the key
- Vs. security through obscurity
- Dvd encryption
- Never roll your own crypto
  - AES
  - RSA
  - Diffie-Hellman
Keyspace
- Number of bits
- Guess how many on average in order to crack?
- Cloud crackers
- Tesla key-fob attack
One-time pad
- Requirements:
  - Must be perfectly random
  - Pad must be as long as the message
  - Must be used only once
Snake-oil
Pseudo-random number generators
- Lava-lamp
  - Sources of entropy
- Seed to get same random numbers each time
  - Seed becomes the secret
Stream cipher
- XOR with prng-stream
- How WAP work
Demo of aes babington plot
Block cipher
- Examples
  - Aes
  - Blowfish
  - Des
- Mode of operation
  - Ecb
    - You can still see the penguin
  - Cbc
    - Initialization-vector
Hashing
- Provides integrity
- One-way, therefore no key
  - Happy birthday to the ground
- Use in password storage
- Fixed-size output
- Avalanche effect
- Collision-resistance – birthday effect
- Flame malware, the work of apt Equation Group (the NSA tailored operations unit), used md5 hash collision to hijack microsoft update process
  - Microsoft was still using known-broken md5 for certificate authenticity verification
- Sha-1 migration to sha-2 migration to sha-3
  - Google threatened that websites that used outdated sha1 would show a security error when users visited those sites in Chrome

Cryptography – Supplemental

Understand binary, hex

Cryptography – Asymmetric

Key-sharing problem for symmetric encryption
- Number of pairs – metcalf’s law
- Difficult to share keys
Diffie-Hellman and the Discrete Logarithm problem
- Used to exchange a key, which is then used for symmetric
- Problem:
  - Still have to negotiate key for each pair
  - no authentication
RSA
- Ron rivest, adi shamir, leonard adleman
- Trapdoor one-way function – extremely difficult to reverse, unless you have the key
  - Prime number factorization with extremely large numbers
    - E.g., 4096-bit product of two primes
- Uses:
  - Encryption
  - Digital Signing
    - Authentication + non-repudiation
    - Hash a message, sign hash with private key, can be verified by applying public key to hash and them hashing
- Problems:
  - Dang slow (x1000)
  - Key sizes must be much larger because attack is different compared to symmetric
Solution: combine asymmetric with symmetric
- Perfect forward secrecy – must not use asymmetric to encrypt the key… only for authentication. Use ephemeral DH for key exchange
- Lavabit’s mistake
- Heartbleed
Quantum computing vs (asymmetric and symmetric encryption)

Cryptography – Digital Certificates

X.509
- Centralized authority with control over root certificates
- Dadgum symantec being sloppy with their root cert
- Stuxnet used two stolen root certs
Pgp certs
- Phil zimmerman, released PGP, federal scrutiny, MIT published source code as a book, did govt really want to sue MIT? Decided no.
- Decentralized cert, therefore dadgum key signing parties, oh what fun
- Failure from social network standards
Signal
- Funding from DoD
- Approved for use by US Senate
- Protocol built into WhatsApp, Facebook Messenger, and now Skype

Authentication and Passwords

Gaining access involves:
- Identification
- Authentication
- Authorization
Authentication
- Something you know
  - passwords
- Something you have
  - Key, debit card, signet ring, rsa keyfob
- Something you are
  - Biometrics (fingerprint, retina scan), secret answer questions, walking gait, facebook trusted contacts
Passwords
- Why they continue to exist despite being weakest link
- Tips
  - Password manager
  - Passphrases
- Password reuse is why hacks and leaks of podunk sites is bad
iPhone, authenticate with either password or fingerprint. Does two authentication attack-vectors make the overall scheme less secure?
Multi-factor authentication

Password Cracking

Function of two input: entropy and speed
Entropy
- Measured in bits
- Measure of uncertainty
- Keyspace is upper bound
- Where do encryption keys come from? Do you memorize a 128-bit number to log into facebook etc?
- General calculation of entropy of a password
- Password leaks => rules for password cracking programs
- Know your memes: “correct horse battery staple”
- Changes in password best practices from 2017 (seriously, know these, and make the companies you work at start employing them, for crying out loud)
Speed
- Online vs offline attack
Salting
- Why? (mitigate rainbow table attack)
- Peppering
  - (seriously who comes up with these names. Who sits around and visualizes shaking spices onto computer things)
Targeted attack – dossier

Vulnerability Scanning

Know your meme: nmap in the movies
Steps:
1. Passive Recon
2. Active scanning
Goal: learn the network. Defender’s advantage is that they know their network and you do not. So learn it.
- Sweep network to enumerate assets
  - For each asset, enumerate ports
    - For each service listening on a port, learn version of software
      - Look up vulnerabilities
What is a port and do I own a boat to dock in said port
Management goal: minimize attack surface

Exploitation

Vocab: bugs, vulnerabilities, exploits, zero days
Bug bounty programs (e.g., hackerone)
Shady vuln market – e.g., zerodium, exploithub,
What is metasploit, what does it contain generally, etc

Hardening

Software updating == patching
Some patches bring new features, some fix bugs
Some bugs are vulnerabilities
Some vulnerabilities are exploitable
That nation states find exploits and weaponize them without alerting vendors (e.g., microsoft), and that nation states get pwned by groups who sell their spoils to other nation states, that the NSA got its pet-tool Eternal Blue stolen and freaked and told Microsoft about it and that they should patch it, and Microsoft freaked and emergency-issued a patch even back for the we-swear-we-will-never-issue-another-patch-for-it Windows XP, yet of course few actually patched, and then North Korea said “hey this exploit looks cool” and made wannacry out of it, and the world got wrecked, and then Russia said “that was a cool thing you did North Korea, we’ll do it too” and months later ran NotPetya and wrecked the world again, and then finally years later anything that can be wrecked by eternal blue has already been wrecked, and you had the honor of running wannacry on your laptops, drawing the attention and panic and probably-ire of CU campus security.
Why is patching hard? – Wendy Nather (It’s not just laziness, but it’s not not laziness either)
Management: Patch your dadgum systems
- But assume that you’ll be compromised anyway

Physical Security

There can be no information security without physical security
Principles:
- Terse
  - Deter
  - Detect
  - respond
- verbose
  - Deter
  - Detect
  - Alarm
  - delay
  - Respond
Defense in depth
Mitigations – full-disk encryption, shredding, remote erase, cameras, door locks, man trap
Lock picking
- basics – tension wrench, SLP, rake, bump key
- Code of conduct
  - Don’t pick a lock you don’t own
  - Don’t pick a lock you rely on

Human Element

Wet-ware, 8th layer of OSI model
Social engineering
- Phishing
  - Spear phishing
  - Defense:
    - 2fa, token-based
    - Training
- Vishing
- Human brain susceptibility to ignoring security warnings
  - Dual-task interference
  - habituation
- Mitnick’s methods
  - Phone call
    - Gain trust
    - Offer to give help
    - Ask for help
  - Goal is to obtain information or access
Security training
- What does it involve
- Why is it hard – Sisyphean task

Network Security Monitoring

Incident response Intersection of security and forensics
Dwell time and discovery
Schneier says: Monitor first
Prevent, but assume prevention failure
Kill-chain concept – stop attacker before they accomplish their goal, and defenders win
Incident response as hand-to-hand crime-scene combat
Practice of NSM – collect everything, full visibility
- Network taps
- Mapping a network
- General concept of the need to be mindful about placement of taps so that true host IPs can be identified (because otherwise, problem of NAT translation)
Principle of a defensible network
- Can be watched
- Can be audited
- Can be inventoried
- Limit an intruder’s freedom to maneuver
- Offer a limited number of services
- Can be kept current
How to justify getting a CIRT
- Why is it hard
- Key metrics, including which ones we identified as being amazing, and which ones we thought wouldn’t work (class discussion)

Information Security in Organizations

Technology vs organization vs people domains
- Subtopics within each domain
Organization
- CEO
  - Responsible to tone at top
- CIO
  - Prime directives, and how they clash with security needs
- CISO
  - Major responsibilities:
    - Incident response
    - Digital forensics
    - Red teaming
    - SETA
    - Secure software development (bake raisins into the dadgum bread, do not sprinkle on top after baking loaf)
    - Physical security
    - Regulatory compliance
  - Where in hierarchy
    - Under CIO?
    - Straight to CEO?
    - Straight to board or to Chief Risk Officer?
- Employees
  - Information security policies (ISPs)
  - Insider Threat. Continuum of intent for ISP violation
    - Passive, non-volitional
    - Volitional but not malicious
    - Intentional, malicious

Malware Analysis

Know Notpetya, Wannacry, Stuxnet because they are modern history
Worm vs virus vs trojan
- These are functionalities, and a malware can have more than one)
Common types
- Wiper
- Ransomware
- Keylogger
- Banking trojan
- etc
James bond villain Evgeniy Bogachev, FBI wanted list, purported author and manager of infamous Zeus trojan
Ransomware and how to protect against it
- Maybe pay ransom so keep cryptocurrency on hand?
- Backups?
  - Hot site
  - Cold site
  - Tapes
Analysis
- Goals
  - Understand scope,
  - Understand behavior,
  - Understand how to detect
- Analysis
  - Static
  - Dynamic
  - Memory
- Remediation
  - Wipe and re-image / re-store
- Protect against
  - Antivirus (yeah right, useless against zero-days)

XSS

Run arbitrary web scripts in victims’ browsers
Reflected vs stored
Common uses:
- Steal login session cookies
- Skim credit card data
- Website defacement
  - All hail ncage
- Malicious redirects
How companies can mitigate
- Various ways, including sanitize inputs

SQLi

Understand on a basic conceptual level that it allows databases to be pilfered by letting attackers run arbitrary database commands through unsanitized user input fields or urls
If you understand https://xkcd.com/327/ you’ll be fine
How companies can mitigate
- Various ways, including sanitize inputs

Security and Terrorism

The five steps from Beyond Fear for threat modeling
- Asset identification
- Risk to asset identification
- Security solution – Effectiveness for mitigating identified risks
- security solution – caused risks
- Security solution – tradeoffs
Specious security-liberty tradeoff

Information Privacy

Reasons how information security relates to information privacy
- Same tools used for both
- Assets that companies are trying to protect have privacy implications
- Specious argument that security and privacy are a tradeoff
  - Btw this is a very good book. Law-professor-level stuffy, but compact and excellent: https://www.danielsolove.com/nothing-to-hide/
Vocab: PII and PHI because you’ll look silly if you don’t know what those stand for
Behavioral tracking business model
- How do advertisers track customers across websites – Third-party cookies

Number One Priorities if you are in charge of infosec in an organization

Monitor first (NSM) <== most number 1
Implement and manage patch management
Implement and manage backup solution
Remind yourself every day to not roll your own crypto (put picture of dvd john on your cubicle and in your wallet)