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Lab 4

The document describes commands to view and modify user accounts and passwords on a Linux system. It creates new users, views and edits password and shadow files, and uses john to crack passwords. Key steps include creating users yoda and chewbaca, viewing passwd and shadow files, installing and using john to crack passwords with default wordlists and view cracked hashes, and changing chewbaca's password to test cracking it with john.

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27 views4 pages

Lab 4

The document describes commands to view and modify user accounts and passwords on a Linux system. It creates new users, views and edits password and shadow files, and uses john to crack passwords. Key steps include creating users yoda and chewbaca, viewing passwd and shadow files, installing and using john to crack passwords with default wordlists and view cracked hashes, and changing chewbaca's password to test cracking it with john.

Uploaded by

21110267
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
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Download as DOCX, PDF, TXT or read online on Scribd
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1.

To view the contents of the passwd file, type:


seed@ubuntu:~$ cat /etc/passwd

2. View the permissions on the /etc/passwd file by typing the following command:
seed@ubuntu:~$ ls -l /etc/passwd

3. To view the contents of the shadow file, type:


seed@ubuntu:~$ sudo cat /etc/shadow
4. To create a new user named yoda, type the following command in the terminal:
seed@ubuntu:~$ sudo adduser yoda (then enter password green)

5. To create a new user named chewbacca, type the following command in the
terminal:
seed@ubuntu:~$ sudo adduser chewbaca (then enter password green)

6. Now, view the changes made to the passwd file by typing the following:
seed@ubuntu:~$ tail /etc/passwd

7. Next, examine the alterations to the shadow file by typing the following:
seed@ubuntu:~$ tail /etc/shadow
8. Examine the entries in the auth.log related to account changes by typing:
seed@ubuntu:~$ tail /var/log/auth.log

9. Next, examine the alterations to the shadow file by typing the following:
seed@ubuntu:~$ tail –n 2 /etc/shadow

10. Examine the entries in the auth.log related to account changes by typing:
seed@ubuntu:~$ tail /var/log/auth.log

11. To look for specific information about password changes within auth.log, type:
seed@ubuntu:~$ cat /var/log/auth.log | grep changed

12. Install john by typing the following command:


seed@ubuntu:~$ sudo apt-get install john
13. Type the following command to see available switches for the john command:
seed@ubuntu:~$:john
14. Type the following command to attempt to crack the passwords with john:
seed@ubuntu:~$:sudo john /etc/shadow
15. To view the password hashes and corresponding passwords, type the following:
seed@ubuntu:~$ sudo cat /root/.john/john.pot
16. Type the following command to attempt to crack the passwords with john
seed@ubuntu:~$ sudo john /etc/shadow
17. Type the following command to remove the existing john.pot file:
seed@ubuntu:~$ sudo rm /root/.john/john.pot
18. Type the following command to re-crack the passwords with john
seed@ubuntu:~$sudo john /etc/shadow
19. . To view the first 20 lines of the file, type the following command in the terminal:
seed@ubuntu:~$ head -n 20 /usr/share/john/password.lst
20. Set chewbacca’s password to computer by typing computer twice after typing:
seed@ubuntu:~$ passwd chewbaca
21. Type the following to run john again and the new password hash will be loaded.
seed@ubuntu:~$ john /etc/shadow --wordlist=/usr/share/john/password.lst
22. To view the last 20 lines of the file, type the following command in the terminal:
seed@ubuntu:~$ tail password.lst
23. Set chewbaca’s password to 1q2w3e4r by typing twice after typing:
seed@ubuntu:~$ passwd chewbaca Type the following to run john again and the new
password hash will be loaded:
seed@ubuntu:~$ john /etc/shadow --wordlist=/usr/share/john/password.lst

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