Important Files relevant to ALL Linux distributions

Key-Files Security

• Introduction - Topology - Features
  • Discuss areas of concern
  • Expose available systems
  • Prepare to study important files
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• Boot Partition
  • Identify /boot setup on various systems
  • Enumerate key files regarding boot sequence
  • Peruse various configuration files
  • Present hypothetical areas of failure
  • Contrast with Windows boot implementation
•  
• INIT Environment
  • Discuss traditional INIT implementation
  • Identify important files across distributions
  • Examine INIT.D and RC hierarchies
  • Propose methods of ensuring integrity of environment
•  
• Kernel Modules Environment
  • Identify key directory hierarchy
  • Discuss applicability
  • Explore various modules related configuration files
  • Enumerate loaded modules and correlate to FS taxonomy
  • Correlate detected modules to loaded and available modules
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• PROC File System
  • Discuss usage and applicability
  • Descend PROC hierarchy accordingly
  • Identify PID tree and related descriptors
  • Recover Kernel invocation method
  • Expose supported Paritions, File Systems & Devices
  • Dump CPU & Memory configuration
  • Peruse other applicable PROC entries
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• SBIN Executables
  • Identify available SBIN containers
  • Expose SETGID and SETUID SBIN entries
  • Enumerate relevant client system binaries
  • Locate important SBIN daemons | services
  • Discuss storage management SBIN entries
  • Find interface and network related SBIN entries
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• System Control Configuration
  • Explain applicability
  • Identify user space process
  • Enumerate default configuration directives
  • Define common variables influencing system behavior
  • Committ variables for persistence
  • Discuss potential areas of concern with system configuration
  • Evaluate results
•  
• INETD | XINETD Configuration
  • Explain super server usage
  • Identify both INETD and XINETD on relevant systems
  • Expose controlled services
  • Disable superfluous super-server controlled services
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• User Accounts Environment
  • Discuss relevance of securing related files
  • Explain default files
  • Suggest areas of concern regarding compromised entries
  • Tighten default security policy related to user accounts
•  
• Pluggable Authentication Modules (PAM)
  • Identify key files related to PAM AUTH
  • Expose baseline configuration based on current definition
  • Locate baseline PAM libraries and discuss strategies
  • Compare and contrast environmental differences across accounts
•  
• Hosts | Protocols | Services
  • Explain relevance of these key files
  • Discuss typical name resolution process
  • Identify baseline confguration
  • Affect changes to relevant files and evaluate
  • Discuss typical malware impact on key files
•  
• NSSWITCH Configuraton
  • Explain importance and relevance
  • Identify various implementations
  • Make changes to name resolver configuration
  • Evaluate results
•  
• DNS Client Resolution Configuration
  • Identify key files governing client resolution
  • Perform queries with incorrect resolution
  • Correct resolution accordingly
  • Vary configuration and evaluate results
•  
• User Profiles Environment
  • Discuss applicable entries related to profiles
  • Delineate between system-wide and user-wide configurations
  • Examine relevant profile files for $SHELL and GUI environments
  • Posit suggestions to tighten baseline
  • Evaluate accordingly
•  
• System Scheduler Environment
  • Discuss importance of CRON
  • Identify system and user-wide configuration files
  • Propose methods of tightening configuration
  • Evaluate resuls
•  
• DNS Server Configuration
  • Discuss importance of traffic direction services
  • Identify key files across distributions
  • Suggest areas to enhance security posture
  • Intersperse corrupt DNS values and evaluate influence
•  
• SYSLOG Configuration
  • Discuss applicability
  • Review baseline configuration
  • Hypothesize possible data-leakage opportunities
  • Propose methods of configuration augmentation
•  
• SSH | Client | Server | Files
  • Discuss importance of file correlation
  • Identify key client files
  • Change client file data and evaluate behavior
  • Identify outdated key file information
  • Generate usage keys and propagate
  • Test communications
  • Identify key server files
  • Discuss implications of SSH configuration
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• '/run' - '/var/run'
  • Discuss 'tmpfs' features
  • Explore implementation
  • Find all PIDs
  • Correlate to running processes
  • Identify various ancillary, non-PID files
  • Explore important items
•  

Sums

• Various Tools
• Remote Confirmations
• File Metadata
• File Fragments
• Compress Content
• Archive Content
• DIR Hierarchy
• Password Sums
• Shared Secret
• Restrict History
• Downloaded Content
• Encrypt Content
• Site Credentials
• Site COOKIE
• Site COOKIE - Unique

CentOS9x Stream Administration

• Initial Environment
• ls, pwd, cd, cp, mv, rm, mkdir, rmdir, whoami
• alias, cat, file, chmod, chown, history
• STD(IN|OUT), Pipes, Redirection, Command Chaining
• ps, df, top, free
• Pagers, W-Commands
• Checksums
• Awk | Sed | Grep Usage
• BASH SHELL Environment
• Compression | Archival Tools
• SSH Equivalence
• SHELL Quoting
• Propagate Environment
• Secure Clients

• Identify Standard File Types
• Standard File Permissions
• Symbolic Links
• Transfer Permissions

• Identify SWAP environment
• Provision dedicated SWAP partitions
• Add | Remove SWAP from pool as needed
• Provision File System-based SWAP
• SWAP Share
• SWAP Persistence
• Identify default storage configuration
• Provision new storage as needed
• XFS - File System
• XFS - Grow File System
• Identify LVM defaults
• Add new partitions to LVM management
• Allocate storage to LVM Volume Groups
• Create Logical Volumes (LVs) as needed
• Overlay File System and mount where applicables
• LVM - Resize
• LVM - Mixed FS
• LVM - SWAP

• Features
• Install
• Defaults
• General Usage
• Update Accounts

• Defaults
• Shared PASS Gen
• Unique PASS Gen
• Encrypted PASS Gen
• Update Accounts
• Groups

• Discuss features | limitations
• Identify default system-wide schedule
• Peruse various default Cron Jobs
• Schedule simple job and monitor recurrence
• Evaluate results

• Peruse Default CONF
• Discuss Syslog Rules
• Explore Log Rotate defaults
• Ensure rotated logs are compressed
• Extend default retention scheme
• Force Log Rotation as needed

• Explore Default environment
• Install PKGs
• Dump important metadata from packages
• Apply Updates

• Default CONF
• Add | Confirm IPs as needed

• Install
• Copy Configuration
• SELinux - Confirm
• TLS | SSL Services
• cURL Client Tests
• Virtual Hosts
• ENC Sites Only

• SFTP Only USER
• SFTP Only USER - NOLOGIN
• SFTP Only Group - Control
• NMap Intro

SysLOG with rSysLogD

• Discuss Features
• Default Environment
• Kernel Firewall LOG
• Split LOGs by Priorities
• UDP | TCP Logging
• Dual L4 Logging
• Multiple Hosts
• Basic Queueing
• Reliable Event Logging Protocol (RELP)
• RELP - Remote Only
• RELP Only
• Traditional to RELP
• SysLOG Clear-Text - Confirm
• Property Filters
• Expression Filters
• Relay Chain

Netfilter Tables

• Features
• SSHGuard
• Ruleset Basics
• Persistence
• Sample Rules
• Inbound Filtering
• Dormant Table
• Manage Tables | Chains | Rules
• Counters
• Sets
• LOG Basics
• LOG with Sets
• Closed-Port LOGs
• LOG Options
• Re-Route LOGs
• Jump Targets
• Chain Jumping
• GoTo Chains
• Meta Selectors

Debian 12x Administration

• Features
• Download
• Graphical Install
• Text Install
• Post-Install Tweaks

• Explore usage of the following useful commands
• tty | /dev/pts | w | whoami | who
• set | env | export | unset
• cat | echo | touch | rm
• pwd | ls | cd | mkdir | alias | umask
• head | tail
• dd
• find
• history
• STDIN, STDOUT, STDERR, UNIX Pipes, Redirection, Command Chaining
• ps, df, free, top, dd
• stat, which, w, who
• tar | gzip | bzip2 | xz
• ZSH Setup

• Network Tools | IP Configuration
• Examine default IP configuration
• Extend IP configuration to facilitate additional addresses
• Static IP Config
• Dual: Dynamic | Static Config
• Multiple Interfaces
• Dual Network Services
• Confirm communications

PHP One-Liners

• General Usage
• Count Lines
• Word Count
• Count Chars
• Split Lines into ARRAY
• Count Instances of Fields
• Transform Delimiters
• Anonymize LOGs
• Extract Unique SRCs
• Lines by Error Code
• LOG By Code
• Summarize Error Codes
• Pre-Seed Error Codes
• Random Strings
• Varied Passwords
• Expose Undefined Passwords
• Outdated Passwords
• Hash | Un-Hash

Cloud Storage with GlusterFS

• Discuss Features:
• Default Volume Type
• Common Volume Types
• Transport Types
• File System Support
• Storage Model

• Features
• Provision Storage
• Allocate GlusterFS Brick
• Persistence
• Generate IO
• Multiple File Systems
• Various Sizes
• Stop | Remove Volume
• Reconstitute Volume
• Server Mount
• Evaluate

OpenPGP with GPG

• Discuss Features:
• Primary Tool
• Private | Public Keys
• Public Key Cryptography Standards (PKCS)
• Encryption | Decryption
• Signing | Verification

• Features
• General Usage
• Create Content
• Encrypt
• PassPhrase Protect
• Binary | Text Encryption
• Share
• Decrypt

SSL-TLS with OpenSSL

• Discuss Features:
• Primary Tool
• Private | Public Keys
• Certificate Signing Requests (CSRs)
• Self-Signed Certificates
• Public Key Cryptography Standards (PKCS)
• Encryption | Decryption
• Random String Generation
• Message Digests
• SSL-TLS Client

• Features
• General Usage
• Retrieve Site Certificates
• Determine OCSP Configuration
• Probe supported TLS Versions
• Extract Certificate for local usage
• Retrieve Certificate with NMap
• Retrieve Certificate Chain

• Discuss
• Generate Private Keys
• Generate Correlating CSRs
• Confirm Keys | CSRs
• Self-Signed Certificates

SSH Variables

• Discuss Features
• Bare VARs
• SSH Client
• Double Quotes
• Single Quotes
• SSH Environment

SHELL Variables

• Discuss Features
• Terminal (TTY)
• CLI Arguments
• Process ID
• Backgrounded
• SHELL Local
• Environment
• Persistence
• Aliases
• Command Substitution
• Increment | Decrement
• Dynamism