Week 2 - Users and Groups Flashcards
Different between standard user, admin, groups?
standard user: limited access, can’t install software or change certain settings
admin: complete control, can view every file and account
groups: users grouped by access level
What application do you use to view user and group information? W
Computer management
What’s a Windows domain? What’s included?
a network of computers, users, and files that are configured on a central database
What does UAC stand for? What does it do?
User Access Control
It prevents unauthorized changes to a system
Do you have to be logged in all the time as an administrator? What makes this possible?
No, don’t have to be logged in as Admin can be logged in on your acccount
UAC helps make this possible
What command lets you quickly see a list of users on the computer?w
Get-LocalUser
(useful to check if admin is turned on for that computer)
What command lets you quickly see a list of groups on the computer? w
Get-LocalGroup
What windows command lets you see who is in a certain group?
Get-LocalGroupMember (group name)
What are the 3 windows commands to see user and group permissions?
- Get-LocalUser
- Get-LocalGroup
- Get-LocalGroupMember (group name)
What is a root user in Linux?
A root user is the first default superuser that is created when an OS is installed
Why is always being logged into an admin or root account dangerous?
There are many important files that could be accidentally deleted or modified
What does sudo mean? l
sudo means superuser do
Where in a command do you place sudo?l
at the front
sudo cat /home/users
When would you have to use sudo?l
When you want to access a root-restricted file
What does su mean? L
substitute user
What’s the function of su? What happens when you use it? L
this changes you to a different user, if none is specified then it goes to root by default
How do you view memberships for all groups in Linux? Find out who can access run sudo?
cat /etc/group
What are the 4 fields when viewing memberships for groups on Linux?
- group name
- group password
- group ID
- users in the group
What’s the file path of the location of the file that contains user information (local)? linux
cat /etc/passwd
How do you tell Bash you want to run a command as root? 2
Trying to run /etc/sudoers but permission error
sudo /etc/sudoers
or
sudo su - (changes you to the substitute default root user) then run the command again
Since computers don’t identify a group or user by its name, how does it identify them?
Group or User IDs (UID)
How do you view a root-restricted file?
sudo cat /file/location
or
sudo su -
then cat filelocation
How would you use the substitute user command to run a root-restricted file?
sudo su -
then run the restricted file command again
What is root’s UID?
0
Why do so many users pop up when we use /etc/password to view users on our local machine?
There are a lot of processes constantly running that our computer needs to associate with a user
What are the 3 main relevant fields in the standard output of cat /etc/passwd?
- user name
- user password
- user ID(UID)
How do you set a password for a user manually on the GUI?
Windows
computer management > right click user > click set password
What Windows command lets you change a local user password?
net
What are two ways to use a command line to change a password? Windows
net user ‘set_password’
net user *
Which method is better for changing a user password when required to change it manually? Windows
net user *
is better because if you type your password out it’s going to be included in the log file in the central database and also prevents wandering eyes from seeing your new password
What’s the windows command to force a user to change their password at next logon?
net user vanes /logonpasswordchg:yes
in Windows, what makes up a strong password? 5 things
- lowercase letters
- uppercase letters
- non-alphanumeric symbols
- Unicode
- numerals
What are “hashes”?
password representations
What does LM hash mean?
LAN Manager hash
What are the two types of hashes? (password represenations) W
- LAN Manager (LM)
- NTLM
Why are there 2 types of hashes? W
to continue backward compatibility with older OS and older applications like Windows 98
How is the MD4 hash generated?
It takes the plain text password and generates a MD4 hash from it
What does MD4 stand for?
Message Digest 4
What is the SAM database? Windows
(local) Security Accounts Manager database
What does concatenate mean?
To bind or join together
Which hash is more resistant to brute force attacks?
The NTLM hash is much more resistant to brute force attacks than the LM hash
What is an offline brute force attack?
Similar to dictionary attacks but doesn’t use passwords included in the text file used in those attacks
attacker uses an automated program that generates hashes or encrypted values for all possible passwords and compares them to the values in the password file.
What is an offline dictionary attack?
Attacker gets offline copy of file where the password is stored and uses an automated program to crack the password (very quickly)
What is an online dictionary attack?
Attacker has a text file with a list of words and uses an automated program that repeatedly tries to log on using those words
What is entropy?
state of disorder. random.
what is password entropy?
random in range and order of the characters to make it harder to crack
What are 3 methods to make a brute force attack-resistant password?
- Use ALT key combos
- Do not start with the top keyboard row alphanumeric symbols !@#$%^&*()_+=
- Do not place symbol entropy in the 8th position as only entropy
What type of account would need a very secure password?
domain administrator
using Unicode characters
How do you enter unicode characters? On PC and laptop
Windows
ALT + 3-4 digit number
laptop: FN + ALT + 3-4 digit number
Do any unicode characters make a password weaker? Why?
Yes, they are converted into ASCII characters
After how long should passwords be changed?
42 days
How do you identify what computer OS are in use in your organization? How do you find that info on a computer?
Windows
Start > Run > Open > winver.exe > OK > Version # displayed
Which OS supports 128 characters and ALT Key combos? 4
Windows
Windows NT 4.0, Windows 2000, Windows XP, Windows Server 2003
What OS supports spaces in your password? windows
Windows NT 4.0, Windows 2000, Windows XP, Windows Server 2003
What are 5 tips for making a password secure?
- Don’t be afraid to make it long by using a pass phrase
- Use the first letter of each word in a phrase
- Replace letters with alphanumeric symbols
- Avoid using complete words
- Choose public or personal upcoming events to make it easier to remember mixed with symbols
What are the 4 don’ts when making passwords?
- Don’t create similar ones to previously used ones
- Don’t use words that are spelled forward or backward in any language
- Don’t use personal information
- Don’t tie the password to the month
What’s the command to change your password in Linux?
passwd
In which location is a scrambled Linux password stored?
/etc/shadow
What does the -e flag mean when applying it to passwords?
windows
-e = expire
What should you do immediately after creating a user or changing a user’s password manually?
windows
Force them to change their password on next logon with:
net user username /logonpasswordchg:yes
How do you add a new local user command?
windows
net user username * /add
then
net user username /logonpasswordchg:yes
How do you add a new local user and require next logon password change in one command line?
windows
net user username pa5sw0rd /add /logonpasswordchg:yes
What are 2 ways you can remove a user in Windows?
- net user username /del
- Remove-LocalUser username
How do you add a user on Linux?
sudo useradd username
How do you force a password change on logon in Linux?
sudo passwd -e username
How do you delete a user on Linux?
sudo userdel username
What are mobile device management policies?
apply and enforce rules about how device has to be configured
require mobile devices to be locked
