Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
CNIT 124:
Advanced Ethical
Hacking
Ch 9: Password Attacks
Topics
• Password Management
• Online Password Attacks
• Offline Password Attacks
• Dumping Passwords from RAM
Password Management
Password Alternatives
• Biometrics
• Two-factor
authentication
• Digital
certificates
Common Password Errors
• Short passwords
• Using dictionary words
• Re-using passwords
– Attackers know that a stolen pass...
Password Reset
• A weak spot
for cloud
services,
especially
free ones
Online Password Attacks
Multiple Logins
• Scripts try to login with passwords from a
list
• Can be blocked by lockout policies
– After five failed...
Wordlists
• Usernames
– Look at valid account names, try to deduce
the pattern
– CCSF uses first letter of first name, the...
Password Lists
• Packetstorm
• For special
purposes
• Openwall has
more general
ones, but
they cost
money
– Link Ch 9d
Targeting Wordlists
• Use information about the targeted
person
• Such as a Facebook page
• Generate passwords from clues
...
Cewl
• Included in Kali
• Creates wordlist from URL, reading words from
pages
Crunch
• Generates a wordlist from characters you
specify (included in Kali)
Hydra
• Online password cracker
• Can use wordlists or pattens
Offline Password Attacks
Getting the Hashes
• Most operating systems and Web services
now hash passwords
– Although some use plaintext, and most us...
Two Ways to Strengthen Hashes
• Salting
– Add random bytes before hashing
– Store them with the hash
– This prevents attac...
SAM and SYSTEM Files
Unavailable when Windows is Running
Win 7 Backup Files
• Also unavailable when system is running
• Win XP had C:WindowsRepair but it
seems to be gone now
Reg.exe
• Works on Windows 7
– Link Ch 8i
SAM is Encrypted
• 128-bit RC4
Key is in SYSTEM
• apt-get install bkhive FAILS on Kali 2
• Must install old versions of bkhive and
samdump2 (link Ch 8l)
Extracting Hashes
• LM Hash on the left (now obsolete)
• NT hash on the right (designed in 1991)
Linux Boot Disk
• You can gather hashes by booting the
target system from a LiveCD or USB
• Copy the files while Windows i...
Cracking Windows Passwords
• Hashcat tests 500,000 passwords in a few
seconds
– Because algorithm is 1 round of MD4
– Proj...
Kali's Password Hashes
• 5000 rounds of SHA-512 with a salt
• Mac OS X is the same
Cracking Kali Hashes
• Can only try 500 words in a few seconds
John the Ripper & Hashcat
• Cracks many types of hashes
– Auto-detects the algorithm
– Can perform brute force, or diction...
CloudCracker
• Moxie
Marlinspike's
service
• Runs on AWS
machines
Cheap!
Mimikatz Gets Clear Passwords from
RAM
Stolen Password Lists
• Lists of millions of real stolen passwords are
now available
• The rockyou list is included in Kal...
Passphrases are Vulnerable
• Hashed with MD5 (link Ch 9g)
• Link Ch 9h
Dumping Passwords from RAM
Plaintext Passwords
• Windows stores the password of the
currently logged-on user in RAM with
"reversible encryption"
• It...
Analysis of Stolen Data Dumped by
TEAMGHOSTSHELL on Aug 25, 2012
Password Storage:

Awful Beyond Belief
Plaintext, obvious, all the same
Plaintext Passwords, Easily Guessed
Sparklan Passwords
Beforward Transactions with PII
Plaintext Passwords
Password Storage:

BASE64
Obfuscated, not hashed
Beforward.jp
BASE64 Encoding
Password Storage:

Unsalted MD5 or SHA-1
Real hashing, but very easy to
crack
MIT – MD5 Password Hashes
MySQL323 Password Hashes
Cracking Hashes with Cain
SHA-1 Hash
Cracked!
MySQL 5 Password Hashes
Wordpress Password Hashes
Relative Space
Cracked!
Password Hashing Algorithms
Hashing Passwords
• Three essential steps
– One-way hash function
• MD5, SHA-1, SHA-256, etc.
– Salt
• Random characters a...
The Right Way
Popular Password Hashes
Type
Projected time to
crack 1,000 hashes*
Hash

Function
Salt

(# chars)
Stretching

(# rounds)
D...
CNIT 124: Ch 9: Password Attacks
CNIT 124: Ch 9: Password Attacks
CNIT 124: Ch 9: Password Attacks
CNIT 124: Ch 9: Password Attacks
CNIT 124: Ch 9: Password Attacks
CNIT 124: Ch 9: Password Attacks
CNIT 124: Ch 9: Password Attacks
CNIT 124: Ch 9: Password Attacks
Upcoming SlideShare
Loading in …5
×

CNIT 124: Ch 9: Password Attacks

454 views

Published on

Slides for a college course in "Advanced Ethical Hacking" at CCSF. Instructor: Sam Bowne

Course Web page:

https://samsclass.info/124/124_F17.shtml

Published in: Education
  • DOWNLOAD FULL BOOKS INTO AVAILABLE FORMAT ......................................................................................................................... ......................................................................................................................... 1.DOWNLOAD FULL PDF EBOOK here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL EPUB Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL doc Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL PDF EBOOK here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL EPUB Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... 1.DOWNLOAD FULL doc Ebook here { https://tinyurl.com/y8nn3gmc } ......................................................................................................................... ......................................................................................................................... ......................................................................................................................... .............. Browse by Genre Available eBooks ......................................................................................................................... Art, Biography, Business, Chick Lit, Children's, Christian, Classics, Comics, Contemporary, Cookbooks, Crime, Ebooks, Fantasy, Fiction, Graphic Novels, Historical Fiction, History, Horror, Humor And Comedy, Manga, Memoir, Music, Mystery, Non Fiction, Paranormal, Philosophy, Poetry, Psychology, Religion, Romance, Science, Science Fiction, Self Help, Suspense, Spirituality, Sports, Thriller, Travel, Young Adult,
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • Be the first to like this

CNIT 124: Ch 9: Password Attacks

  1. 1. CNIT 124: Advanced Ethical Hacking Ch 9: Password Attacks
  2. 2. Topics • Password Management • Online Password Attacks • Offline Password Attacks • Dumping Passwords from RAM
  3. 3. Password Management
  4. 4. Password Alternatives • Biometrics • Two-factor authentication • Digital certificates
  5. 5. Common Password Errors • Short passwords • Using dictionary words • Re-using passwords – Attackers know that a stolen password can often be re-used elsewhere
  6. 6. Password Reset • A weak spot for cloud services, especially free ones
  7. 7. Online Password Attacks
  8. 8. Multiple Logins • Scripts try to login with passwords from a list • Can be blocked by lockout policies – After five failed logins, must wait an hour • Brute-forcing is possible – Trying every combination of characters – Impractical except for very short passwords
  9. 9. Wordlists • Usernames – Look at valid account names, try to deduce the pattern – CCSF uses first letter of first name, then last name, then 2 digits, like psmith01 – Find a list of real usernames, or use a list of common names
  10. 10. Password Lists • Packetstorm • For special purposes • Openwall has more general ones, but they cost money – Link Ch 9d
  11. 11. Targeting Wordlists • Use information about the targeted person • Such as a Facebook page • Generate passwords from clues – TaylorSwift13!
  12. 12. Cewl • Included in Kali • Creates wordlist from URL, reading words from pages
  13. 13. Crunch • Generates a wordlist from characters you specify (included in Kali)
  14. 14. Hydra • Online password cracker • Can use wordlists or pattens
  15. 15. Offline Password Attacks
  16. 16. Getting the Hashes • Most operating systems and Web services now hash passwords – Although some use plaintext, and most use weak hashing techniques • Windows stores hashes in an encrypted C: WindowsSAM file, but the key is available in the SYSTEM file
  17. 17. Two Ways to Strengthen Hashes • Salting – Add random bytes before hashing – Store them with the hash – This prevents attackers from pre-computing 'Rainbow Tables" of hashes • Stretching – Many rounds, typically 5000, of hashing – Slows down attackers
  18. 18. SAM and SYSTEM Files
  19. 19. Unavailable when Windows is Running
  20. 20. Win 7 Backup Files • Also unavailable when system is running • Win XP had C:WindowsRepair but it seems to be gone now
  21. 21. Reg.exe • Works on Windows 7 – Link Ch 8i
  22. 22. SAM is Encrypted • 128-bit RC4
  23. 23. Key is in SYSTEM • apt-get install bkhive FAILS on Kali 2 • Must install old versions of bkhive and samdump2 (link Ch 8l)
  24. 24. Extracting Hashes • LM Hash on the left (now obsolete) • NT hash on the right (designed in 1991)
  25. 25. Linux Boot Disk • You can gather hashes by booting the target system from a LiveCD or USB • Copy the files while Windows is not running
  26. 26. Cracking Windows Passwords • Hashcat tests 500,000 passwords in a few seconds – Because algorithm is 1 round of MD4 – Proj X16 in CNIT 123
  27. 27. Kali's Password Hashes • 5000 rounds of SHA-512 with a salt • Mac OS X is the same
  28. 28. Cracking Kali Hashes • Can only try 500 words in a few seconds
  29. 29. John the Ripper & Hashcat • Cracks many types of hashes – Auto-detects the algorithm – Can perform brute force, or dictionary, or modified dictionary attacks • Hashcat is newer and claims to be faster • oclHashcat – Designed to run in parallel on many GPUs
  30. 30. CloudCracker • Moxie Marlinspike's service • Runs on AWS machines
  31. 31. Cheap!
  32. 32. Mimikatz Gets Clear Passwords from RAM
  33. 33. Stolen Password Lists • Lists of millions of real stolen passwords are now available • The rockyou list is included in Kali – in /usr/share/wordlists – Link Ch 9e
  34. 34. Passphrases are Vulnerable
  35. 35. • Hashed with MD5 (link Ch 9g)
  36. 36. • Link Ch 9h
  37. 37. Dumping Passwords from RAM
  38. 38. Plaintext Passwords • Windows stores the password of the currently logged-on user in RAM with "reversible encryption" • It can be recovered with Windows Credential Editor or mimikatz • No matter how long or complex it is
  39. 39. Analysis of Stolen Data Dumped by TEAMGHOSTSHELL on Aug 25, 2012
  40. 40. Password Storage:
 Awful Beyond Belief Plaintext, obvious, all the same
  41. 41. Plaintext Passwords, Easily Guessed
  42. 42. Sparklan Passwords
  43. 43. Beforward Transactions with PII
  44. 44. Plaintext Passwords
  45. 45. Password Storage:
 BASE64 Obfuscated, not hashed
  46. 46. Beforward.jp
  47. 47. BASE64 Encoding
  48. 48. Password Storage:
 Unsalted MD5 or SHA-1 Real hashing, but very easy to crack
  49. 49. MIT – MD5 Password Hashes
  50. 50. MySQL323 Password Hashes
  51. 51. Cracking Hashes with Cain
  52. 52. SHA-1 Hash
  53. 53. Cracked!
  54. 54. MySQL 5 Password Hashes
  55. 55. Wordpress Password Hashes
  56. 56. Relative Space
  57. 57. Cracked!
  58. 58. Password Hashing Algorithms
  59. 59. Hashing Passwords • Three essential steps – One-way hash function • MD5, SHA-1, SHA-256, etc. – Salt • Random characters added to each password • Prevents rainbow-table attack – Stretching • Repeat the hash function many times (typically 5000) • Make it take 50 ms to calculate the hash • Minimally slows login • Makes attack MUCH slower
  60. 60. The Right Way
  61. 61. Popular Password Hashes Type Projected time to crack 1,000 hashes* Hash
 Function Salt
 (# chars) Stretching
 (# rounds) Drupal 7 1.7 years SHA-512 8 16385 Linux (Debian) 58 days SHA-512 8 5000 Wordpress 3.5.1 17 hours MD5 8 8193 Windows
 (all current versions) 5.4 min MD4 None 1 Joomla 4.6 min MD5 16 1 • Calculation assumes the passwords are found in a dictionary of 500,000 guesses • One virtual machine running Kali • A clusters of GPUs would be much faster

×