Seven Domains of IT

21 Jan 2022

Seven Domains of a Typical IT Infrastructure

• User - deals with authentication
• Workstation - the computer/office
• LAN - segmentation and authentication
• LAN to WAN - our access point to the Internet, ingress/egress filtering with firewalls, IDS . . .
• WAN
• Remote Access Domain - hotels, coffee shop . . . vpns are important here for encryption
• System/Application Domain - Databases, web servers, application servers . . . this is what attackers are after, so need good encryption

Linux Folder Structure

• /dev - pointers to storage and IO systems
• /etc - admin, password and shadow files
• /home
• sbin - admin binaries like daemons
• /usr - unique files to user

Linux Password Architecture

• /etc/passwd - text file, human-readable, the x is where the password would be
• /etc/shadow - hashed passwords, everyone can read but only root can change it (though I’m not sure why you would)
  • Colon-delimited, user is at the beginning and then after colon is the hashed password, followed by some metadata
  • Metadata includes minimum and maximum days required between valid passwords/password changes
  • Hashed password = "$id$salt$hashed"
    • ID identifies the type of hash, like $6 is SHA512
    • Salt is random data added

Windows Password Architecture

Password Cracking

• Active online - actively trying to guess online passwords
• Passive online - sniffing, running a program online
• Offline - dictionary-style, hybrid, brute-force

John the Ripper

• Built into cyberrange
• john shadow_file first time, john --show shadow_file to dump the info again

Assignments

• Lab 1 posted soon
• Read chapter 2 of book