Detecting abnormal listening ports with PowerShell

Introduction: Understanding Listening Ports and Security Implications

Listening ports are crucial endpoints in your system's network infrastructure where services await incoming connections. Monitoring these ports is essential for maintaining system security and detecting potential threats. This guide demonstrates how to leverage PowerShell's native capabilities to identify and analyze listening ports without requiring additional software installation.

Native Windows Tools for Port Monitoring

PowerShell's Get-NetTCPConnection Cmdlet

The Get-NetTCPConnection cmdlet is a powerful native PowerShell tool that provides comprehensive information about network connections. As highlighted in Microsoft's documentation, this cmdlet offers more detailed insights compared to traditional tools like netstat.

# Basic command to list all listening ports
Get-NetTCPConnection -State Listen

# Detailed listening ports with associated processes
Get-NetTCPConnection -State Listen | Select-Object LocalAddress, LocalPort, State, OwningProcess, @{Name="ProcessName";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}}

Advanced Filtering and Analysis

To identify potentially suspicious listening ports, use these PowerShell commands:

# Filter for non-standard high ports
Get-NetTCPConnection -State Listen | Where-Object {$_.LocalPort -gt 49152} | 
Select-Object LocalPort, @{Name="ProcessName";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}}

# Identify processes using multiple listening ports
Get-NetTCPConnection -State Listen | 
Group-Object -Property OwningProcess | 
Where-Object {$_.Count -gt 1} | 
ForEach-Object {
    $processName = (Get-Process -Id $_.Name).ProcessName
    [PSCustomObject]@{
        ProcessName = $processName
        PortCount = $_.Count
        Ports = ($_.Group | Select-Object -ExpandProperty LocalPort) -join ', '
    }
}

Detecting Abnormal Port Activity

Identifying Suspicious Patterns

Look for these warning signs when analyzing listening ports:

• Unexpected high-numbered ports in listening state
• Known services running on non-standard ports
• Multiple listening ports owned by the same process
• Services listening on all interfaces (0.0.0.0) unnecessarily

Automated Monitoring Script

# Create a baseline of normal listening ports
$baseline = Get-NetTCPConnection -State Listen | Select-Object LocalPort, OwningProcess

# Function to compare current state against baseline
function Compare-ListeningPorts {
    $current = Get-NetTCPConnection -State Listen | Select-Object LocalPort, OwningProcess
    $differences = Compare-Object -ReferenceObject $baseline -DifferenceObject $current -Property LocalPort
    
    if ($differences) {
        foreach ($diff in $differences) {
            $port = $diff.LocalPort
            $process = (Get-Process -Id (Get-NetTCPConnection -State Listen | Where-Object LocalPort -eq $port).OwningProcess).ProcessName
            Write-Warning "New listening port detected: Port $port used by process $process"
        }
    }
}

Best Practices for Port Monitoring

Regular Auditing Procedures

Implement these monitoring practices:

1. Establish a baseline of normal listening ports in your environment
2. Document all authorized services and their expected ports
3. Regularly compare current listening ports against the baseline
4. Investigate any deviations from the established baseline immediately

Response Procedures

When detecting suspicious listening ports:

• Identify the associated process and verify its legitimacy
• Check process signatures and file paths
• Monitor network traffic patterns for the suspicious port
• Document and investigate any unauthorized changes

Understanding and Detecting Abnormal Listening Ports with PowerShell

Network security professionals need to regularly monitor listening ports to identify potential security threats and ensure system integrity. This guide demonstrates how to leverage native Windows PowerShell commands to detect and analyze listening ports without requiring additional software installation.

Essential PowerShell Commands for Port Analysis

Using Get-NetTCPConnection

The primary cmdlet for analyzing network connections and listening ports is Get-NetTCPConnection. This powerful native command provides detailed information about all TCP connections and listening ports. Here's how to use it effectively:

# Get all listening ports
Get-NetTCPConnection -State Listen

# Filter listening ports with specific properties
Get-NetTCPConnection -State Listen | Select-Object LocalAddress,LocalPort,State,OwningProcess

Identifying Process Information

To correlate listening ports with their associated processes, use this enhanced command:

Get-NetTCPConnection -State Listen | Select-Object LocalAddress,LocalPort,State,OwningProcess,@{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).Name}} | Sort-Object LocalPort

Analyzing Common vs. Suspicious Ports

Well-Known Port Ranges

• System Ports (1-1023): Reserved for standard system services
• User Ports (1024-49151): Registered for specific applications
• Dynamic Ports (49152-65535): Used for temporary connections

Creating a Baseline Detection Script

Use this script to identify potentially suspicious listening ports:

# Create a baseline detection script
$commonPorts = @(80,443,135,445,3389,5985)
$suspiciousPorts = Get-NetTCPConnection -State Listen | 
    Where-Object {$_.LocalPort -notin $commonPorts} |
    Select-Object LocalPort,
        @{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).Name}},
        @{Name="Path";Expression={(Get-Process -Id $_.OwningProcess).Path}}

# Display suspicious listening ports
$suspiciousPorts | Format-Table -AutoSize

Advanced Port Monitoring Techniques

Real-Time Port Monitoring

Implement continuous monitoring with this PowerShell script:

while($true) {
    Clear-Host
    Write-Host "Current Listening Ports - $(Get-Date)" -ForegroundColor Green
    Get-NetTCPConnection -State Listen |
        Select-Object LocalPort,
            @{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).Name}},
            @{Name="CreationTime";Expression={(Get-Process -Id $_.OwningProcess).StartTime}} |
        Sort-Object LocalPort |
        Format-Table -AutoSize
    Start-Sleep -Seconds 5
}

Port Change Detection

Monitor for new listening ports with this comparison script:

# Create initial snapshot
$initial = Get-NetTCPConnection -State Listen | Select-Object LocalPort

# Monitor for changes
while($true) {
    Start-Sleep -Seconds 10
    $current = Get-NetTCPConnection -State Listen | Select-Object LocalPort
    
    $newPorts = Compare-Object -ReferenceObject $initial -DifferenceObject $current -Property LocalPort |
        Where-Object {$_.SideIndicator -eq "=>"}
    
    if($newPorts) {
        Write-Host "New listening ports detected:" -ForegroundColor Red
        $newPorts | Format-Table -AutoSize
    }
    
    $initial = $current
}

Best Practices for Port Analysis

Regular Monitoring Guidelines

• Establish a baseline of normal listening ports in your environment
• Document all authorized applications and their expected ports
• Implement regular automated scans using the provided scripts
• Investigate any unexpected listening ports immediately

Response Procedures

When detecting suspicious ports, follow these steps:

1. Document the unexpected listening port and associated process
2. Verify the process path and digital signature
3. Check process creation time and parent process
4. Investigate network connections associated with the process

Monitoring listening ports through PowerShell provides a powerful, native method for detecting potential security threats. By implementing these scripts and following the outlined best practices, security professionals can maintain effective oversight of their network infrastructure without relying on third-party tools.

Using PowerShell to Monitor and Analyze Listening Ports

This comprehensive guide demonstrates how to leverage PowerShell's native capabilities to identify, analyze, and detect potentially suspicious listening ports on Windows systems. These techniques require no additional software installation and utilize built-in Windows PowerShell cmdlets.

Basic Port Enumeration Commands

Using Get-NetTCPConnection

The primary PowerShell cmdlet for port analysis is Get-NetTCPConnection, which provides detailed information about all TCP connections. Here's the basic syntax:

Get-NetTCPConnection | Where-Object State -eq 'Listen' | Select-Object LocalAddress,LocalPort,State,OwningProcess

Enhanced Output Formatting

To get more detailed information, including the process name associated with each port:

Get-NetTCPConnection -State Listen | 
Select-Object LocalAddress,LocalPort,State,@{
    Name='ProcessName';
    Expression={(Get-Process -Id $_.OwningProcess).ProcessName}
} | 
Format-Table -AutoSize

Advanced Port Analysis Techniques

Filtering for Specific Conditions

To identify potentially suspicious ports, use these targeted commands:

# List ports with non-standard high port numbers
Get-NetTCPConnection -State Listen | 
Where-Object {$_.LocalPort -gt 49152} |
Select-Object LocalPort,OwningProcess,@{
    Name='ProcessName';
    Expression={(Get-Process -Id $_.OwningProcess).ProcessName}
}

Creating a Baseline for Normal Operations

Establish a baseline of normal port activity with this script:

$baseline = Get-NetTCPConnection -State Listen | 
Select-Object LocalPort,OwningProcess,@{
    Name='ProcessName';
    Expression={(Get-Process -Id $_.OwningProcess).ProcessName}
} |
Export-Csv -Path "C:\baseline_ports.csv" -NoTypeInformation

Detecting Abnormal Port Activity

Automated Port Monitoring Script

Use this script to detect new listening ports:

$knownPorts = Import-Csv "C:\baseline_ports.csv"
$currentPorts = Get-NetTCPConnection -State Listen | 
Select-Object LocalPort,OwningProcess,@{
    Name='ProcessName';
    Expression={(Get-Process -Id $_.OwningProcess).ProcessName}
}

$newPorts = $currentPorts | Where-Object {
    $port = $_.LocalPort
    -not ($knownPorts | Where-Object {$_.LocalPort -eq $port})
}

if ($newPorts) {
    Write-Host "New listening ports detected:" -ForegroundColor Red
    $newPorts | Format-Table -AutoSize
}

Common Port Analysis Scenarios

Identifying Remote Access Ports

Monitor commonly used remote access ports:

$remoteAccessPorts = @(22,23,3389,5900)
Get-NetTCPConnection -State Listen | 
Where-Object {$_.LocalPort -in $remoteAccessPorts} |
Select-Object LocalPort,@{
    Name='ProcessName';
    Expression={(Get-Process -Id $_.OwningProcess).ProcessName}
},State

Analyzing Process-to-Port Relationships

Investigate processes with multiple listening ports:

Get-NetTCPConnection -State Listen | 
Group-Object -Property OwningProcess | 
Where-Object {$_.Count -gt 1} |
ForEach-Object {
    $process = Get-Process -Id $_.Name
    [PSCustomObject]@{
        ProcessName = $process.ProcessName
        ProcessId = $process.Id
        PortCount = $_.Count
        Ports = ($_.Group | Select-Object -ExpandProperty LocalPort) -join ','
    }
} |
Format-Table -AutoSize

Best Practices for Port Monitoring

• Regularly update your baseline of normal port activity
• Document all authorized applications and their expected ports
• Implement automated monitoring for new listening ports
• Investigate any unexpected listening ports immediately
• Maintain logs of port activity changes over time

Introduction to Identifying Abnormal Listening Ports

Network security professionals must regularly monitor and analyze listening ports to identify potential security risks and malicious activities. This guide demonstrates how to leverage native Windows PowerShell commands to detect and investigate abnormal listening ports without installing additional software.

Understanding Normal vs. Abnormal Port Behavior

Common Legitimate Windows Ports

Before identifying abnormal ports, understand the standard Windows service ports:

• Port 20/21 (FTP)
• Port 22 (SSH)
• Port 80/443 (HTTP/HTTPS)
• Port 135 (RPC)
• Port 139/445 (SMB)
• Port 3389 (RDP)

PowerShell Commands for Port Analysis

Basic Port Enumeration

Get-NetTCPConnection -State Listen | Select-Object LocalAddress,LocalPort,State,OwningProcess | Sort-Object LocalPort

This command displays all listening TCP ports, sorted by port number for easy analysis.

Advanced Filtering for Suspicious Ports

# Filter for high-numbered ports (potentially suspicious)
Get-NetTCPConnection -State Listen | Where-Object {$_.LocalPort -gt 49152} | 
Select-Object LocalAddress,LocalPort,State,@{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}}

Identifying Suspicious Port Patterns

Red Flags to Monitor

• Unexpected high-numbered ports (above 49152)
• Known malware ports
• Multiple listening ports from the same process
• Unauthorized services on standard ports

Process-to-Port Correlation

# Get detailed process information for listening ports
Get-NetTCPConnection -State Listen | ForEach-Object {
    $process = Get-Process -Id $_.OwningProcess
    [PSCustomObject]@{
        LocalAddress = $_.LocalAddress
        LocalPort = $_.LocalPort
        ProcessName = $process.ProcessName
        ProcessPath = $process.Path
        CommandLine = (Get-CimInstance Win32_Process -Filter "ProcessId = $($_.OwningProcess)").CommandLine
    }
} | Format-Table -AutoSize

Regular Monitoring Script

Automated Port Analysis

# Create a baseline snapshot
$baseline = Get-NetTCPConnection -State Listen | Select-Object LocalAddress,LocalPort,State,OwningProcess

# Compare current state with baseline
$current = Get-NetTCPConnection -State Listen | Select-Object LocalAddress,LocalPort,State,OwningProcess
$differences = Compare-Object -ReferenceObject $baseline -DifferenceObject $current -Property LocalPort

# Display new listening ports
$differences | Where-Object {$_.SideIndicator -eq '=>'} | 
ForEach-Object {
    Get-NetTCPConnection -State Listen | 
    Where-Object {$_.LocalPort -eq $_.LocalPort} | 
    Select-Object LocalAddress,LocalPort,@{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}}
}

Investigating Suspicious Ports

Detailed Analysis Steps

Review process connections:

Get-NetTCPConnection -OwningProcess [process_id] | Select-Object LocalAddress,LocalPort,RemoteAddress,RemotePort,State

Check process details and signed status:

Get-Process -Id [process_id] | Select-Object *
Get-AuthenticodeSignature -FilePath "[process_path]"

Identify the process using the suspicious port:

Get-Process -Id (Get-NetTCPConnection -LocalPort [suspicious_port] -State Listen).OwningProcess

Detecting Abnormal Listening Ports Using Native PowerShell Commands

This technical guide covers the process of identifying and analyzing listening ports using PowerShell's native capabilities, enabling security professionals to detect potentially malicious network activity without requiring additional software installation.

Understanding PowerShell's Network Analysis Capabilities

Core PowerShell Cmdlets

The primary cmdlet for port analysis in PowerShell is Get-NetTCPConnection, which provides detailed information about TCP connections and listening ports. This cmdlet is part of the native Windows networking stack and requires no additional installations.

Get-NetTCPConnection -State Listen | Select-Object LocalPort, State, OwningProcess

Basic Port Analysis Commands

Listing All Listening Ports

To get a comprehensive view of all listening ports:

# Display all listening ports with associated processes
Get-NetTCPConnection -State Listen | 
Select-Object LocalPort, State, OwningProcess, @{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}} |
Sort-Object LocalPort

Filtering and Formatting Results

For enhanced analysis, use PowerShell's filtering capabilities:

# Filter for specific port ranges
Get-NetTCPConnection -State Listen | 
Where-Object {$_.LocalPort -ge 1024} |
Select-Object LocalPort, @{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}},
@{Name="PathName";Expression={(Get-Process -Id $_.OwningProcess).Path}} |
Format-Table -AutoSize

Advanced Port Analysis Techniques

Cross-Referencing with Process Information

Create a detailed analysis of listening ports and their associated processes:

# Detailed process and port analysis
$connections = Get-NetTCPConnection -State Listen
foreach ($conn in $connections) {
    try {
        $process = Get-Process -Id $conn.OwningProcess
        [PSCustomObject]@{
            LocalPort = $conn.LocalPort
            ProcessName = $process.ProcessName
            ProcessPath = $process.Path
            Company = $process.Company
            ProductVersion = $process.ProductVersion
        }
    } catch {
        Write-Warning "Could not get details for process ID $($conn.OwningProcess)"
    }
} | Format-Table -AutoSize

Identifying Suspicious Port Usage

Common Legitimate Port Usage

Reference table for standard Windows services and their expected ports:

Service              Port    Process
----------------------------------------------------------------------------------------
HTTP                 80      System or w3wp.exe
HTTPS               443     System or w3wp.exe
RDP                 3389    svchost.exe
SMB                 445     System
DNS                 53      svchost.exe
LDAP                389     lsass.exe

Detecting Anomalous Ports

Script to identify potentially suspicious port usage:

# Check for uncommon high ports
$suspiciousPorts = Get-NetTCPConnection -State Listen | 
Where-Object { 
    $_.LocalPort -gt 49152 -and 
    (Get-Process -Id $_.OwningProcess).ProcessName -notin @('System', 'svchost', 'lsass')
} | 
Select-Object LocalPort, 
    @{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}},
    @{Name="Path";Expression={(Get-Process -Id $_.OwningProcess).Path}}

if ($suspiciousPorts) {
    Write-Warning "Suspicious high ports detected:"
    $suspiciousPorts | Format-Table -AutoSize
}

Automated Port Monitoring

Creating a Monitoring Script

Implementation of a continuous monitoring solution:

# Continuous port monitoring script
$knownPorts = @{
    80 = "HTTP"
    443 = "HTTPS"
    3389 = "RDP"
    445 = "SMB"
}

while ($true) {
    $currentPorts = Get-NetTCPConnection -State Listen |
        Select-Object LocalPort, 
            @{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}}
    
    foreach ($port in $currentPorts) {
        if (-not $knownPorts.ContainsKey($port.LocalPort)) {
            Write-Warning "New listening port detected: $($port.LocalPort) - Process: $($port.Process)"
        }
    }
    Start-Sleep -Seconds 300
}

Troubleshooting and Common Pitfalls When Monitoring Ports with PowerShell

This comprehensive guide addresses common challenges and solutions when using PowerShell's native capabilities to detect abnormal listening ports on Windows systems. Understanding these potential pitfalls is crucial for effective network monitoring and security assessment.

Common Permission-Related Issues

ExecutionPolicy Restrictions: Ensure proper execution policy is set

# Check current execution policy
Get-ExecutionPolicy
# If needed, set to appropriate level (in admin PowerShell):
Set-ExecutionPolicy -ExecutionPolicy RemoteSigned

Insufficient Privileges: Many network monitoring commands require administrative rights

# Run PowerShell as Administrator using:
Start-Process PowerShell -Verb RunAs

Filtering and Data Interpretation Mistakes

When using the Get-NetTCPConnection cmdlet, avoid these common filtering errors:

# Incorrect - Too broad filtering
Get-NetTCPConnection | Where-Object State -eq "Listen"

# Correct - Specific filtering with multiple parameters
Get-NetTCPConnection -State Listen | Select-Object LocalAddress, LocalPort, State, OwningProcess | Sort-Object LocalPort

Process Association Errors

A frequent mistake is not correlating ports with their associated processes:

# Correct approach - Including process information
Get-NetTCPConnection -State Listen | 
Select-Object LocalAddress, LocalPort, State, OwningProcess, @{
    Name="ProcessName";
    Expression={(Get-Process -Id $_.OwningProcess).ProcessName}
} | Sort-Object LocalPort | Format-Table -AutoSize

Output Interpretation Challenges

• False Positives:Common causes include:
  • Legitimate system services using dynamic ports
  • Temporary listening states during application startup
  • Development environments running local services

Missing Context:Enhance output with additional context:

# Enhanced monitoring with service correlation
Get-NetTCPConnection -State Listen | 
Select-Object LocalAddress, LocalPort, 
@{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}},
@{Name="Service";Expression={
    (Get-WmiObject -Class Win32_Service | 
    Where-Object {$_.ProcessId -eq $_.OwningProcess}).DisplayName
}} | Format-Table -AutoSize

Performance Considerations

Avoid these performance-impacting mistakes:

Inefficient Filtering: Filter early in the pipeline for better performance

# Inefficient
Get-NetTCPConnection | Where-Object {$_.State -eq "Listen" -and $_.LocalPort -gt 1024}

# More efficient
Get-NetTCPConnection -State Listen | Where-Object {$_.LocalPort -gt 1024}

Excessive Polling: Don't query too frequently

# Better approach - Use measured intervals
while($true) {
    Get-NetTCPConnection -State Listen |
    Select-Object LocalPort, State, OwningProcess
    Start-Sleep -Seconds 30
}

Best Practices for Accurate Monitoring

• Always verify process ownership and service correlation
• Maintain a baseline of normal port usage
• Document legitimate applications and their expected port usage
• Use error handling for robust scripts

# Example of proper error handling
try {
    Get-NetTCPConnection -State Listen -ErrorAction Stop |
    Select-Object LocalAddress, LocalPort, State,
    @{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}} |
    Format-Table -AutoSize
} catch {
    Write-Warning "Error accessing network information: $_"
    Write-Warning "Ensure you have administrative privileges"
}

Introduction to PowerShell Port Monitoring

PowerShell provides robust native capabilities for monitoring and analyzing listening ports on Windows systems. This guide demonstrates how to leverage built-in PowerShell cmdlets to detect potentially malicious or abnormal port activity without requiring additional software installation.

Essential PowerShell Commands for Port Detection

Using Get-NetTCPConnection

The primary cmdlet for port monitoring is Get-NetTCPConnection, which provides detailed information about TCP connections and listening ports. Here's how to use it effectively:

# Display all listening ports
Get-NetTCPConnection -State Listen

# Filter for specific states and display detailed information
Get-NetTCPConnection -State Listen | Select-Object LocalPort, State, OwningProcess

Identifying Process Information

To correlate ports with their associated processes:

# Get detailed process information for listening ports
Get-NetTCPConnection -State Listen | Select-Object LocalPort, State, OwningProcess, @{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}}

Creating Monitoring Scripts

Basic Port Monitoring Function

function Monitor-ListeningPorts {
    $baselineSnapshot = Get-NetTCPConnection -State Listen | 
        Select-Object LocalPort, OwningProcess, 
        @{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}}
    
    Write-Host "Monitoring for new listening ports..."
    
    while($true) {
        Start-Sleep -Seconds 30
        $currentPorts = Get-NetTCPConnection -State Listen |
            Select-Object LocalPort, OwningProcess,
            @{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}}
        
        $newPorts = Compare-Object -ReferenceObject $baselineSnapshot -DifferenceObject $currentPorts -Property LocalPort |
            Where-Object {$_.SideIndicator -eq "=>"}
        
        if($newPorts) {
            Write-Host "New listening ports detected:" -ForegroundColor Red
            $newPorts | ForEach-Object {
                $port = $_.LocalPort
                $process = ($currentPorts | Where-Object {$_.LocalPort -eq $port}).Process
                Write-Host "Port: $port - Process: $process" -ForegroundColor Yellow
            }
        }
    }
}

Advanced Detection Techniques

Identifying Suspicious Port Patterns

# Function to detect uncommon high ports
function Find-SuspiciousPorts {
    $commonPorts = @(80,443,3389,445,139,135)
    Get-NetTCPConnection -State Listen | 
    Where-Object { 
        $_.LocalPort -notin $commonPorts -and 
        $_.LocalPort -gt 1024 
    } | 
    Select-Object LocalPort, 
        @{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}},
        @{Name="Path";Expression={(Get-Process -Id $_.OwningProcess).Path}}
}

Automated Port Baseline Creation

# Create and save a baseline of normal port activity
function New-PortBaseline {
    $baseline = Get-NetTCPConnection -State Listen | 
        Select-Object LocalPort, 
        @{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}},
        @{Name="Path";Expression={(Get-Process -Id $_.OwningProcess).Path}}
    
    $baseline | Export-Csv -Path "$env:USERPROFILE\port_baseline.csv" -NoTypeInformation
    Write-Host "Baseline saved to $env:USERPROFILE\port_baseline.csv"
}

Best Practices for Continuous Monitoring

• Regularly update your port baseline to account for legitimate changes in your system
• Implement logging mechanisms to track port changes over time
• Create alerts for specific port ranges that shouldn't normally have listening services
• Document all authorized services and their expected port numbers

Conclusion

Maintaining vigilant port monitoring is crucial for system security. By leveraging PowerShell's native capabilities, administrators can effectively detect and respond to abnormal port activity without relying on third-party tools. Regular monitoring, combined with proper baseline management and alert systems, provides a robust first line of defense against potential security threats.

Sources

• Adam the Automator - PowerShell Port Monitoring Guide
• AttuneOps - PowerShell Security Best Practices
• MSHub - Find Listening Ports With Netstat and PowerShell
• TomTalksPowerShell - Network Configuration and Troubleshooting
• Comprehensive Guide to Get-NetTCPConnection
• ITechtics Port Monitoring Guide
• PowerShell Security Best Practices
• Microsoft Official Documentation - Get-NetTCPConnection
• MSHub - PowerShell Port Analysis Guide
• Microsoft Hub - PowerShell Network Analysis Guide
• AdamTheAutomator - Advanced Port Analysis Techniques
• PowerShell Network Connection Management Guide
• TCP Port Response Checking with PowerShell
• Microsoft Hub - PowerShell Port Analysis Guide
• Splunk Research - PowerShell Network Connection Analysis
• Windows Standard Port Reference