Analysis of leaked LinkedIn dumps, methods of cracking passwords, what hardware do you need and how long it could take, some interesting statistics

1. Yurii Bilyk | 2016
How-to crack 43kk passwords
while drinking your
in the Hood

2. WHO AM I
26 vs 27.5 vs 29

3. TEAM
 WE are Security Group
 WE are ALL Engineers (Almost;)
 WE are OWASP Lviv Chapter
 WE are Legio… oops
blog: http://owasp-lviv.blogspot.com
skype: y.bilyk

4. o But WHY??!!
o Our CRACKING RIG
o Different obvious methods
o Not so obvious methods
o Some interesting statistics
Agenda

5. Tell Me WHY!?
what’s wrong with you?

6. The Reason
Just for FUN
Good example of Open Source
Intelligence
You can really test your skills in
password cracking

7. Some Info
LinkedIn DB contains 250 758 057
e-mails
Only 61 829 208 contains unique
hashes
File size of all unique hashes is
2.5 GB

8. Our CRACKING RIG
because we can

9. P - Podgotovka
LinkedIn DB contains unsalted
SHA-1 hashes
GPU should be best option for
such type of hashes
Best tool for this case is HashCat

11. GTX 1080 SHA-1 Benchmark
8xGPU SHA-1 crack speed:
68 771.0 MH/s
8xCHARS password Z!sN0/7u:
95 symbols length alphabet
6.70 X 1015 search space
1 days 3 hours 4 minutes 54
seconds to brute ALL combinations

12. Question of Money
738x8 = 5904 $$$

14. Amazon K80 SHA-1 Benchmark
36xGPU SHA-1 crack speed:
75 200.0 MH/s
8xCHARS password Z!sN0/7u:
95 symbols length alphabet
6.70 X 1015 search space
1 days 45 minutes 59 seconds to
brute ALL combinations

15. So You’ve said Amazon?
(14.4+14.4+7.2)x25 = 900 $$$

17. Rainbow Alternatives
1000 $$$

18. RainBow Seek SHA-1 Benchmark
SHA-1 crack speed:
3 880 000.0 MH/s for 1 hash
784 000.0 MH/s for 10 hashes
8xCHARS password Z!sN0/7u:
95 symbols length alphabet
6.70 X 1015 search space
28 minutes <-> 2 hours 22 minutes to
brute ALL combinations

20. Return to Reality
Intel Core i5-3570 @ 3.4Ghz
SHA-1 crack speed: ~120.0 MH/s
NVIDIA 750GT (Mobile):
SHA-1 crack speed: ~120.0 MH/s

21. 1xi5-3570 SHA-1 Benchmark
SHA-1 crack speed:
120.0 MH/s
8xCHARS password Z!sN0/7u:
95 symbols length alphabet
6.70 X 1015 search space
1 years 281 days 10 hours 30 minutes
48 seconds to brute ALL combinations

22. Some OBVIOUS STEPS
let’s play

23. Where to Start?
We used dictionary attack as the
first attempt
You need good dictionary. We
started with rockyou.txt
You need memory for your hashes.
It could be problem for GPU

24. So First Try
Cracked around 20% of all hashes
(with rockyou.txt dictionary)
It took around 5 mins 
And now you have to think what
to do next 

25. We need moar dictionaries!
RockYou contains 14 344 391 words
We tried different dictionaries.
The biggest was 1 212 356 398
words and 15 GB in size
All this gives us approx 35% of all
hashes

26. Let’s brute it!
We selected up to 6 char passwords
with full set of characters
It took around 2 hours
All this gives us approx 45% of all
hashes

27. Magic of STATISTICS
new is well-forgotten old

28. What we can do get moar?
HashCat has rules of transformation
It mutates original word
Quality of your dictionary is
essential. Size doesn’t rly matters
Using rules is more time consuming
than just dictionary attack

29. What rules are effective?
We used best64, InsidePro-
PasswordsPro and d3ad0ne rules
It was very effective in terms of
number of hashes
All this gives us approx 60% of all
hashes

30. Time to go smarter way
We have 36 millions of cracked
passwords
We can analyze cracked password
to determine patters
This patterns can produce more
efficient bruteforce masks

31. Meet PACK Tool
http://thesprawl.org/projects/pack/

32. PACK Tool Features
Can analyze list of password and
generate bruteforce mask
You can specify password length,
time, complexity constrains
Gives you some idea what type of
passwords are popular

33. Is PACK effective?
It can crack similar passwords
according that you already have
You can flexibly choose best
masks regarding constrains
All this gives us approx 65% of all
hashes

34. Other types of attacks
PRINCE attack, somehow similar to
the using PACK tool + mutation
Combination of TWO and more
dictionaries
Hybrid attack, that uses
dictionaries + rules + bruteforce
masks

35. Some CHARTS
It’s easy

36. Length of password (Our)

37. Length of password (Korelogic)

38. Character-set of password (Our)

39. Most Popular Passwords (Korelogic)

40. Mails (Korelogic)

41. Base Words (Korelogic)

42. Thank YOU!