Cracking Passwords in Forensic Investigations - Scholarly ...

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sets used, method of attack, how compromised the passwords are, and also the length of passwords (Potter, 2009). An example of L0phtCrack 6‘s report is shown in Figure 2.4. Figure 2.4: An example of reporting in L0phtCrack 6 (Potter, 2009, p.17) 2.3.3 Password Recovery Toolkit & Distributed Network Attack Password Recovery Toolkit (PRTK) and Distributed Network Attack (DNA) are commercially available password-recovery software packages released by AccessData Corp. The target audience for PRTK and DNA are law enforcement agencies, corporate security, and IT professionals. PRTK is also targeted at individual users such as administrators who wish to recover lost passwords. PRTK and DNA are the most powerful and versatile password-recovery programs available on the market. PRTK supports a wide variety of file types and encryption standards; DNA has the same features as PRTK, but supports harnessing the power of several computers for cracking passwords (Casey, 2004; AccessData Corp., 2010). PRTK and DNA support a wide variety of password cracking attacks. Adapted from the Distributed Network Attack and Password Recovery Toolkit user guide by AccessData Corp. (2010), the various attacks these packages support are: 19
i) Decryption attack: As discussed in section 2.2.1, the decryption attack decrypts the password that locks the file. ii) Dictionary attack: As discussed in section 2.2.3, the dictionary attack uses words from the dictionary and also applies variations (or rules) to these words to crack the password. iii) Keyspace attack: In the keyspace attack, each and every possible combination of keys are tried to decrypt the file. iv) Reset: With the reset feature, it is possible to reset the key used for opening the file to a custom key, thus eliminating the need for recovering the key. PRTK and DNA have a wide variety of features. Adapted from the Distributed Network Attack and Password Recovery Toolkit user guide by AccessData Corp. (2010), some of the important features are: i) Hash files: The hash files feature calculates a unique hash value for the file whose password is to be recovered. PRTK and DNA calculate the hash value of the file when it is added for processing. After the password recovery process is over, the hash value is calculated again. If the two hash values calculated before and after the password recovery process match, then it implies that the file‘s contents have remained unchanged during the whole process. Thus, the file-hashing feature is useful for law enforcement personnel to maintain the integrity of evidence (AccessData Corp., 2010, p. 2). ii) Recover multi-language passwords: Multiple language dictionaries are bundled along with PRTK and DNA. Thus, it is possible to recover multi-language passwords (AccessData Corp., 2010, p. 2). iii) Generate reports: PRTK and DNA can print password-recovery job reports in pdf format (AccessData Corp., 2010, p. 2). iv) Open encrypted files: PRTK and DNA support opening encrypted files using recovered passwords. However, the application used for opening the files must be installed on the same computer. Recovered files can also be copied or moved to another location (AccessData Corp., 2010, p. 3). 20
Page 1 and 2: Cracking Passwords in Forensic Inve
Page 3 and 4: iii Acknowledgements This thesis wa
Page 5 and 6: v Abstract Digital Forensic Investi
Page 7 and 8: vii Table of Contents Declaration .
Page 9 and 10: ix Chapter 4 - Research Findings 4.
Page 11 and 12: xi List of Tables Table 2.1: The Mo
Page 13 and 14: xiii List of Abbreviations AMD Adva
Page 15 and 16: 1.1 PROBLEMS FOR DIGITAL FORENSIC I
Page 17 and 18: approach improves the password crac
Page 19 and 20: technologies, there exist challenge
Page 21 and 22: 2.1 PASSWORDS AND PASSWORD RECOVERY
Page 23 and 24: 2.1.2 Unix/Linux MD5 Password Schem
Page 25 and 26: encrypting the information within s
Page 27 and 28: iii) If possible, create a custom d
Page 29 and 30: Since all possible permutations and
Page 31: L0phtCrack 6 supports the retrieval
Page 35 and 36: Full cost refers to the total amoun
Page 37 and 38: As shown in Table 2.3, a password w
Page 39 and 40: 5) Weir, Aggarwal, Medeiros, and Gl
Page 41 and 42: the speed of cracking and the attac
Page 43 and 44: is inevitable) but rather the optim
Page 45 and 46: Klein (1990) addressed the most com
Page 47 and 48: character hashing. Thus, for passwo
Page 49 and 50: experiments were conducted by gener
Page 51 and 52: obtained via phishing attacks on th
Page 53 and 54: Bengtsson (2007) outlined a literat
Page 55 and 56: applications whose passwords need t
Page 57 and 58: equired for computing and testing.
Page 59 and 60: 3.2.3 The Research Questions and Hy
Page 61 and 62: main experiment, which is the next
Page 63 and 64: 12,500 x 8 = 100,000 passwords/seco
Page 65 and 66: 3.3.5 Data Map Figure 3.2: Research
Page 67 and 68: 4.0 INTRODUCTION Chapter 4 Research
Page 69 and 70: 4.1.2 Time Budgeting The time budge
Page 71 and 72: Another computer with the same conf
Page 73 and 74: minutes, and 24.8 days respectively
Page 75 and 76: vishal@vishal-desktop:~$ sudo addus
Page 77 and 78: Table 4.4: Monitoring/action-perfor
Page 79 and 80: 4.3 ANALYSIS OF DATA The experiment
Page 81 and 82: Table 4.6: First 10 accounts’ pas
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DD:HH:MM:SS format, similar to the
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4.4 PRESENTATION OF DATA FINDING Af
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Figure 4.8 shows the time taken for
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Figure 4.11 displays the comparison
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5.0 INTRODUCTION Chapter 5 Research
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Thus, the simulation mirrored the f
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Table 5.1: Testing hypothesis H0 Hy
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Table 5.3: Testing hypothesis H2 Hy
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Q3: What are the guidelines for bes
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Since the passwords were arranged i
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Analysis (see Section 3.2.3). All f
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information for forensic investigat
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5.3.1.2 Second Step - Find Password
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Therefore, T (in seconds) = 12,500,
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6.0 RESEARCH SUMMARY Chapter 6 Conc
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udgets, the passwords were added to
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SECONDARY RESEARCH QUESTION 3: What
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overcome the security barriers of p
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Clayton, R., & Bond, M. (2003). Exp
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Openwall Project. (2010). John the
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APPENDIX 1: Time Budget Calculation
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51 Bas -2-38 TOTAL TIME REQUIRED FO
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96 Bas -2-27 97 Bas -2-28 98 Bas -2
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140 Adv -1-26 141 Bas -3-07 142 Adv
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182 Adv -1-21 183 Adv -1-22 Diction
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main12:$1$CSD0Tppt$0gO4c883evmn9sQR
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main41.txt: main41:$1$B43.jKTn$5EPi
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main70.txt: main70:$1$7kHK0PnH$yJ5x
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main99:$1$UQiTB..u$SJUkwarkM1kzvnvt
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main128.txt: main128:$1$n7OEbAyB$d6
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main157.txt: main157:$1$VRmaYxPu$Iy
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main186:$1$HFNaeUkb$t1lZ5QcrH9iy8G/
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SHA 1: a168282ad70a94fbb8d5917f3505
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C:\Main Test\MainTest-passwdFiles\B
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Job Started: 7/13/10 8:49:24 File M
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File Modified: 7/13/10 6:58:08 SHA
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File Version: Unknown Job Started:
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SHA 1: b95b12e95c70b66df01af148502e
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File Size: 60 File Version: Unknown
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Job Status: Finished on 7/13/10 8:5
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Identified Type: *nix passwd File S
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Password Type: Password Where Found
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Job Status: Finished on 7/13/10 10:
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MD5: df7c66c8b6b8528176d42314926021
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Result: trapezoidal@ Description: U
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Where Found: (ADV-1-20) Dictionary
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Password Type: Password Where Found
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Where Found: (BAS-3-04) Dictionary
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Commonly Registered Type: crypt use
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Where Found: --- C:\Main Test\MainT
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MD5: 17632fca93fa27bb8d0a89c80a2ba9
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Description: Unknown Password Type:
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File Version: Unknown Job Started:
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APPENDIX 4: Time Analysis for all B
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main60 main61 main62 main63 main64
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main127 main128 main129 main130 mai
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main192 main193 main194 main195 mai
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