Le blog technique

<pre class="wp-block-syntaxhighlighter-code">
##############################################
### QUERY CROWDSTRIKE WITH PSFALCON MODULE ###
##############################################


<# 

    .SYNOPSIS 
        INTERROGATION D'UN TENANT FALCON CROWDSTRIKE VIA L'UTILISATION DU MODULE POWERSHELL PSFALCON
        NB: LES DONNEES SONT EXTRAITES SOUS FORME D'UN FICHIERS CSV 

    .PARAMETER  
        ClientID : Client ID crowdstrike
        Pass : Password du compte d'acces a l'API
        
        ExportFolder : Dossier d'export du fichier CSV
        LogFolder : Chemin du dossier où creer le log du script

 
    .EXAMPLE 
     .\QueryCrowdstrike.ps1 -CloudUrl "https://api.eu-1.crowdstrike.com"  -ClientID <clientid> -Pass <pass> -ExportFolder ./ -LogFolder ./
#>


[CmdletBinding()]
param(
[Parameter(Mandatory,HelpMessage="Cloud URL")]
$CloudUrl,

[Parameter(HelpMessage="Client ID crowdstrike")]
$ClientID,

[Parameter(HelpMessage="Password du compte d'acces a l'API")]
$Pass,

[Parameter(Mandatory,HelpMessage="Dossier d'export du fichier CSV")]
[string]$ExportFolder="./CSV",

[Parameter(Mandatory,HelpMessage="Chemin du dossier où creer le log du script")] 
[string]$LogFolder="./",

[Parameter(Mandatory,HelpMessage="Chemin de la clé utilisée pour l'encryption du CID et de la passphrase")] 
$KeyFile = "D:\MyFolder\CROWDSTRIKE\AES.key",

[Parameter(Mandatory,HelpMessage="Chemin du fichier contenant le SecID du client")] 
$SecIDFile = "D:\MyFolder\CROWDSTRIKE\SecID.txt",

[Parameter(Mandatory,HelpMessage="Chemin du fichier contenant la passphrase")] 
$PassFile = "D:\MyFolder\CROWDSTRIKE\Pass.txt"


)


# TO RENEW KEY FILE USED FOR CLIENT ID AND PASSPHRASE ENCRYPTION
<#
    # Generate Key File
    $Key = New-Object Byte[] 16   # You can use 16, 24, or 32 for AES
    [Security.Cryptography.RNGCryptoServiceProvider]::Create().GetBytes($Key)
    $Key | out-file $KeyFile

#>


# TO RENEW SECID ENCRYPTION, EXECUTE THE CODE BETWEEN <# #>

<#
    # Create secure string object
    $SecIDFile = "D:\MyFolder\CROWDSTRIKE\SecID.txt"
    $Key = Get-Content $KeyFile
    $SecID = read-host  -Prompt "Enter client SecID" -AsSecureString
    $SecID | ConvertFrom-SecureString -key $Key | Out-File $SecIDFile

#>


# TO RENEW PASSPHRASE ENCRYPTION, EXECUTE THE CODE BETWEEN <# #>

<#
    # Create secure string object
    $PassFile = "D:\MyFolder\CROWDSTRIKE\Pass.txt"
    $Key = Get-Content $KeyFile
    $Pass = read-host  -Prompt "Enter client PassPhrase" -AsSecureString
    $Pass | ConvertFrom-SecureString -key $Key | Out-File $PassFile

#>






# OTHER VARIABLES
# Script Name
$ScriptName = "QueryCrowdstrike.ps1"
# LogName = ScriptName without extension
$Log = $ScriptName.Split('.')[0]


# FUNCTIONS


function Write-Log 
{ 
    <# 
    .SYNOPSIS 
        This function creates or appends a line to a log file. 
 
    .PARAMETER  Message 
        The message parameter is the log message you'd like to record to the log file. 
 
    .EXAMPLE 
        PS C:\> Write-Log -Message 'Value1' 
        This example shows how to call the Write-Log function with named parameters. 
    #> 
    [CmdletBinding()] 
    param ( 
        [Parameter(Mandatory)] 
        [string]$Message,
        [Parameter(Mandatory)] 
        [string]$LogPath, 
        [Parameter(Mandatory)] 
        [string]$LogName
        
    ) 
     
    try 
    { 
        $DateTime = Get-Date -Format ‘MM-dd-yy HH:mm:ss’ 
        Add-Content -Value "$DateTime - $Message" -Path "$LogPath\$LogName.log" 
    } 
    catch 
    { 
        Write-Error $_.Exception.Message 
    } 
} 



            




# Requis si l'import du module echoue en en renvoyant plusieurs messages 'Unable to find [System.Net.Http.(...)*]' 
Add-Type -AssemblyName System.Net.Http 

# Import Module
Import-Module -Name D:\MyFolder\CROWDSTRIKE\Powershell_Module\psfalcon-master\PSFalcon.psm1



$Key = Get-Content $KeyFile

# Get file content and Decrypt ClientID
$ClientID = Get-Content $SecIDFile | ConvertTo-SecureString -Key $key
$ClientID = [System.Runtime.InteropServices.Marshal]::PtrToStringAuto([System.Runtime.InteropServices.Marshal]::SecureStringToBSTR($ClientID))

# Get file content and Decrypt Pass
$Pass = Get-Content $PassFile | ConvertTo-SecureString -Key $key
$Pass = [System.Runtime.InteropServices.Marshal]::PtrToStringAuto([System.Runtime.InteropServices.Marshal]::SecureStringToBSTR($Pass))







# Query for Falcon Token
try
    {
    Request-FalconToken -ClientId $ClientID -ClientSecret $Pass -Hostname $CloudUrl
    }
catch
    {
    $Message = "Error during Request-FalconToken - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }


# Test if Test-FalconToken return True
if ($(Test-FalconToken).token -eq $true)  
      {
      $Message = "Token is valid - OK"
      write-host -F Green $Message
      Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
      }
Else
    {
    $Message = "Problem with Token - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }




# GET DATA

#region Falcon Hosts 

# Get Falcon Hosts (exemple option -filter:  –Filter "hostname:'SRV'")
try
    {
    $FalconHosts = Get-FalconHost -All -Detailed
    #$FalconHosts | select hostname,os_version,agent_version,status | ft -AutoSize
    }
catch
    {
    $Message = "Problem during Get-FalconHost - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }


# Convert To CSV
 try
    {
    $FalconHostsCSV = $($FalconHosts | select `
        hostname,
        os_version,
        platform_name,
        status,
        agent_version,
        config_id_base,
        config_id_build,
        @{Name='First_Seen';Expression={[datetime]::ParseExact($_.first_seen.Replace('T','').Replace('Z',''),'yyyy-MM-ddHH:mm:ss',$null)}},
        @{Name='Last_Seen';Expression={[datetime]::ParseExact($_.last_seen.Replace('T','').Replace('Z',''),'yyyy-MM-ddHH:mm:ss',$null)}},
        reduced_functionality_mode | ConvertTo-Csv -Delimiter ',' -NoTypeInformation).Replace('"','')
    
    # Display CSV File
    $FalconHostsCSV
    }
catch
    {
    $Message = "Error during convert to CSV file for FalconHosts - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }

# Export CSV
 try
    {   
    $FalconHostsCSV | Out-File -FilePath "$ExportFolder`/FalconHosts.csv" -Force
    }
catch
    {
    $Message = "Error during export of CSV file for FalconHosts - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }


#endregion Falcon Hosts 







#region Falcon Detection




#Get-FalconDetection
write-host "FALCON DETECTION EVENTS" -B White -f Blue
try
    {
    $FalconDetection = Get-FalconDetection -Detailed -All  
    $FalconDetection | sort created_timestamp -Descending
    }
catch
    {
    $Message = "Error during Get-FalconDetection - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }


# Convert To CSV
 try
    {
    $FalconDetectionCSV = $($FalconDetection | select `
    detection_id,
    @{Name='Detection_Creation_Date';Expression={[datetime]::ParseExact($_[0].created_timestamp.split('.')[0].Replace('T',''),'yyyy-MM-ddHH:mm:ss',$null)}},
    @{Name='HostName';Expression={$_.device.hostname}},
    @{Name='HostIP';Expression={$_.device.local_ip}},
    @{Name='DeviceID';Expression={$_.device.device_id}},
    @{Name='BehaviorID';Expression={$_.Behaviors.Behavior_id}},
    @{Name='Behavior_FileName';Expression={$_.Behaviors.filename}},
    @{Name='Behavior_FilePath';Expression={$_.Behaviors.filepath}},
    @{Name='Behavior_cmdline';Expression={$_.Behaviors.cmdline}},
    status,
    max_severity_displayname,
    email_sent | ConvertTo-Csv -Delimiter ',' -NoTypeInformation).Replace('"','')
    }
catch
    {
    $Message = "Error during convert to CSV file for FalconDetection - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }

# Export CSV
 try
    {   
    $FalconDetectionCSV | Out-File -FilePath "$ExportFolder`/FalconDetection.csv"
    }
catch
    {
    $Message = "Error during export of CSV file for FalconDetection - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }




#endregion Falcon Detection




#region Falcon Behavior

# Get-FalconBehavior (NB: Transform TimeStamp to more readable format with [datetime]::ParseExact)
write-host "FALCON BEHAVIOR EVENTS" -B White -f Blue

try
    {
    $FalconBehavior = Get-FalconBehavior | foreach {Get-FalconBehavior -Ids $_} | Select -property  behavior_id,display_name,objective,@{Name='BehaviorDate';Expression={[datetime]::ParseExact($_.timestamp.Replace('T','').replace('Z',''),'yyyy-MM-ddHH:mm:ss',$null)}},cmdline,filepath,user_name,incident_id,tactic_id,tactic,technique_id,technique | sort BehaviorDate -Descending
    $FalconBehavior
    }
catch
    {
    $Message = "Error during Get-FalconBehavior - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }


# Convert To CSV
 try
    {
    $FalconBehaviorCSV = $($FalconBehavior | select BehaviorDate,cmdline,filepath,user_name | ConvertTo-Csv -Delimiter ';' -NoTypeInformation).Replace('"','')
    }
catch
    {
    $Message = "Error during convert to CSV file for FalconBehavior - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }

# Export CSV
 try
    {   
    $FalconBehaviorCSV | Out-File -FilePath "$ExportFolder`/FalconBehavior.csv"
    }
catch
    {
    $Message = "Error during export of CSV file for FalconBehavior - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }



#endregion Falcon Behavior





#region Falcon Incident

write-host "FALCON INCIDENTS EVENTS" -B White -f Blue
try
    {
    $FalconIncidents= Get-FalconIncident -Detailed -All  
    $FalconIncidents | sort created -Descending
    }
catch
    {
    $Message = "Error during Get-FalconIncident - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }


# Convert To CSV
 try
    {
    $FalconIncidentsCSV = $($FalconIncidents | select `
    incident_id,
    @{Name='Creation_Date';Expression={[datetime]::ParseExact($_.created.Replace('T','').Replace('Z',''),'yyyy-MM-ddHH:mm:ss',$null)}},
    state,
    email_state  | ConvertTo-Csv -Delimiter ',' -NoTypeInformation).Replace('"','')



        

    }
catch
    {
    $Message = "Error during convert to CSV file for FalconIncident - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }

# Export CSV
 try
    {   
    $FalconIncidentsCSV | Out-File -FilePath "$ExportFolder`/FalconIncidents.csv"
    }
catch
    {
    $Message = "Error during export of CSV file for FalconIncidents - END OF SCRIPT"
    write-host -F Red $Message
    Write-Log -Message $Message -LogPath $LogFolder -LogName $Log
    EXIT 1
    }




#endregion Falcon Incident
</pre>