Essential Cybersecurity Commands and Techniques for Threat Analysts

Introduction

In today’s evolving threat landscape, cybersecurity professionals must master a range of commands, tools, and techniques to detect, mitigate, and prevent attacks. This article provides verified Linux/Windows commands, cloud security configurations, and threat-hunting methodologies for IT professionals, particularly those in roles like Threat Analyst or Azure Security Engineer.

Learning Objectives

• Execute critical Linux/Windows commands for security analysis.
• Harden cloud environments using Azure security best practices.
• Apply threat-hunting techniques to identify malicious activity.

1. Linux: Analyzing Suspicious Processes

Command:

ps aux | grep -i "suspicious_process" 

What It Does:

Lists all running processes and filters for a specific suspicious name.

Step-by-Step Guide:

1. Open a terminal.

2. Run `ps aux` to view all processes.

1. Pipe (|) the output into `grep -i` to search case-insensitively.
2. Investigate the PID, CPU usage, and executable path of any matches.

2. Windows: Detecting Malicious Network Connections

Command (PowerShell):

Get-NetTCPConnection | Where-Object {$_.State -eq "Established"} | Select-Object LocalAddress, RemoteAddress, OwningProcess 

What It Does:

Displays active network connections and ties them to running processes.

Step-by-Step Guide:

1. Launch PowerShell as Administrator.

1. Run the command to list all established connections.
2. Cross-reference `OwningProcess` with Task Manager or Get-Process -Id

   </code>. </li>
   </ol>
   
   <h2 style="color: yellow;"> 3. Azure: Enforcing Multi-Factor Authentication (MFA)</h2>
   
   <h2 style="color: yellow;">Command (Azure CLI):</h2>
   
   [bash]
   az policy assignment create --name "Enforce-MFA" --policy <MFA-Policy-ID> --scope /subscriptions/<subscription-id> 
   

   What It Does:

   Applies an Azure Policy to enforce MFA across a subscription.

   Step-by-Step Guide:

   1. Install Azure CLI and authenticate (`az login`).

   1. Locate the built-in MFA policy ID via az policy definition list.

   3. Assign the policy to your subscription.

   4. Threat Hunting: Querying Logs for Anomalies

   Command (KQL - Azure Sentinel):

   SecurityEvent 
   | where EventID == 4625 
   | summarize FailedAttempts = count() by Account 
   | where FailedAttempts > 5 
   

   What It Does:

   Identifies brute-force attacks by counting failed login attempts.

   Step-by-Step Guide:

   1. Navigate to Azure Sentinel.

   2. Run the query in the Logs section.

   3. Investigate accounts with excessive failures.

   5. API Security: Testing for Vulnerabilities

   Command (curl):

   curl -X POST https://api.example.com/login -d '{"user":"admin","password":"test"}' -H "Content-Type: application/json" 
   

   What It Does:

   Tests an API endpoint for weak authentication.

   Step-by-Step Guide:

   1. Use `curl` to send a POST request.

   1. Modify payloads to test for SQLi, XSS, or broken authentication.

   3. Analyze responses for errors or unexpected behavior.

   6. Cloud Hardening: Restricting S3 Bucket Permissions

   Command (AWS CLI):

   aws s3api put-bucket-policy --bucket my-bucket --policy file://policy.json 
   

   What It Does:

   Applies a strict access policy to an S3 bucket.

   Step-by-Step Guide:

   1. Define a JSON policy denying public access.

   2. Apply it via AWS CLI.

   3. Verify with `aws s3api get-bucket-policy`.

   7. Vulnerability Mitigation: Patching Linux Systems

   Command:

   sudo apt update && sudo apt upgrade -y 
   

   What It Does:

   Updates all installed packages to the latest secure versions.

   Step-by-Step Guide:

   1. Run `apt update` to refresh package lists.

   2. Use `apt upgrade` to install updates.

   3. Reboot if kernel updates are applied.

   What Undercode Say

   • Key Takeaway 1: Automating security checks (e.g., KQL queries, Azure Policies) reduces manual oversight risks.
   • Key Takeaway 2: Command-line proficiency is non-negotiable for efficient threat detection.

   Analysis:

   The rise of cloud and hybrid environments demands fluency in both OS-level commands and cloud-native tools. Threat analysts must balance reactive (log analysis) and proactive (hardening) measures. Certifications like AZ-500 and eCTHPv2 validate these skills, but hands-on practice with real-world commands is irreplaceable.

   Prediction

   As AI-driven attacks escalate, mastering automated threat detection (e.g., Sentinel KQL, AWS GuardDuty) will become critical. Meanwhile, foundational commands remain the backbone of incident response.

   IT/Security Reporter URL:

   Reported By: Valentina Galea - Hackers Feeds
   Extra Hub: Undercode MoN
   Basic Verification: Pass ✅

   Join Our Cyber World:

   💬 Whatsapp | 💬 Telegram