KillChain_utils.ps1
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# Checks whether the domain has MX records pointing to MS cloud # Jun 16th 2020 # Aug 30th 2022: Fixed by maxgrim function HasCloudMX { [cmdletbinding()] Param( [Parameter(Mandatory=$True)] [String]$Domain ) Process { $results=Resolve-DnsName -Name $Domain -Type MX -DnsOnly -NoHostsFile -NoIdn -ErrorAction SilentlyContinue | select nameexchange | select -ExpandProperty nameexchange $filteredResults=$results -like "*.mail.protection.outlook.com" return ($filteredResults -eq $true) -and ($filteredResults.Count -gt 0) } } # Checks whether the domain has SPF records allowing sending from cloud # Jun 16th 2020 function HasCloudSPF { [cmdletbinding()] Param( [Parameter(Mandatory=$True)] [String]$Domain ) Process { $results=Resolve-DnsName -Name $Domain -Type txt -DnsOnly -NoHostsFile -NoIdn -ErrorAction SilentlyContinue | select strings | select -ExpandProperty strings return ($results -like "*include:spf.protection.outlook.com*").Count -gt 0 } } # Checks whether the domain has SPF records allowing sending from cloud # Sep 23rd 2020 function HasDMARC { [cmdletbinding()] Param( [Parameter(Mandatory=$True)] [String]$Domain ) Process { try { $results=Resolve-DnsName -Name "_dmarc.$Domain" -Type txt -DnsOnly -NoHostsFile -NoIdn -ErrorAction SilentlyContinue | select strings | select -ExpandProperty strings }catch{} return ($results -like "v=DMARC1*").Count -gt 0 } } # Checks whether the domain has DKIM records for Exchange Online # Aug 14rd 2023 function HasCloudDKIM { [cmdletbinding()] Param( [Parameter(Mandatory=$True)] [String]$Domain ) Process { $selectors = @("selector1", "selector2") foreach ($selector in $selectors) { try { $results = Resolve-DnsName -Name "$selector._domainkey.$($Domain)" -Type CNAME -DnsOnly -NoHostsFile -NoIdn -ErrorAction SilentlyContinue if($results.NameHost -like "*_domainkey.*.onmicrosoft.com*") { return $true } }catch {} } return $false } } # Checks whether the domain has MTA-STS records for Exchange Online # Aug 14rd 2023 function HasCloudMTASTS { param ( [string]$Domain ) $url = "https://mta-sts.$Domain/.well-known/mta-sts.txt" $mtaStsFound = $false $outlookMxFound = $false try { $mtaStsResponse = Invoke-WebRequest -Uri $url -ErrorAction Stop $mtaStsContent = $mtaStsResponse.Content $mtaStsLines = $mtaStsContent -split "`r?`n" foreach ($line in $mtaStsLines) { if ($line -like "version: STSv1") { $mtaStsFound = $true } if ($line -like "*mx: *.mail.protection.outlook.com*") { $outlookMxFound = $true } } } catch { $mtaStsFound = $false $outlookMxFound = $false } return ($mtaStsFound -eq $true) -and ($outlookMxFound -eq $true) } # Checks whether the domain has DesktopSSO enabled # Jun 16th 2020 function HasDesktopSSO { [cmdletbinding()] Param( [Parameter(Mandatory=$True)] [String]$Domain ) Process { (Get-CredentialType -UserName "nn@$domain").EstsProperties.DesktopSsoEnabled -eq "True" } } # Checks whether the domain has CBA enabled # Jun 17th 2022 function HasCBA { [cmdletbinding()] Param( [Parameter(Mandatory=$True)] [String]$UserName ) Process { (Get-CredentialType -UserName $UserName).Credentials.HasCertAuth -eq "True" } } # Checks whether the user exists in Azure AD or not # Jun 16th 2020 function DoesUserExists { [cmdletbinding()] Param( [Parameter(Mandatory=$True)] [String]$User, [Parameter(Mandatory=$False)] [ValidateSet("Normal","Login","Autologon","RST2")] [String]$Method="Normal" ) Process { $exists = $false if($Method -eq "Normal") { # Get the credential type information $credType=Get-CredentialType -UserName $User # Works only if desktop sso (aka. Seamless SSO) is enabled # Since August 2021 this seems to work for all tenants! #if($credType.EstsProperties.DesktopSsoEnabled -eq "True") #{ # Return empty if throttling if($credType.ThrottleStatus -eq 1) { Write-Warning "Requests throttled!" Remove-Variable exists } else { $exists = $credType.IfExistsResult -eq 0 -or $credType.IfExistsResult -eq 6 } #} #else #{ # Remove-Variable exists #} } else { if($Method -eq "Login") { # Try to log in as the user $randomGuid = New-Guid $body = @{ "resource"=$randomGuid "client_id"=$randomGuid "grant_type"="password" "username"=$User "password"="none" "scope"="openid" } try { $jsonResponse=Invoke-RestMethod -UseBasicParsing -Uri "https://login.microsoftonline.com/common/oauth2/token" -ContentType "application/x-www-form-urlencoded" -Method POST -Body $body -Headers $headers $exists = $True # May be should change password..? } catch { $errorDetails = ($_.ErrorDetails.Message | convertfrom-json).error_description } } elseif("Autologon","RST2".Contains($Method)) { $requestId = (New-Guid).ToString() $domain = $User.Split("@")[1] $password = "none" $now = Get-Date $created = $now.toUniversalTime().toString("o") $expires = $now.addMinutes(10).toUniversalTime().toString("o") if($Method -eq "RST2") { # RST2 $url = "https://login.microsoftonline.com/RST2.srf" $endPoint = "sharepoint.com" } else { # AutoLogon $url = "https://autologon.microsoftazuread-sso.com/$domain/winauth/trust/2005/usernamemixed?client-request-id=$requestid" $endPoint = "urn:federation:MicrosoftOnline" } $exists = $false try { $response = Get-RSTToken -Url $url -EndpointAddress $endPoint -UserName $User -Password $password $exists = $true # Very bad password } catch { $errorDetails = $_.Exception.Message } } # Parse the error code. Only AADSTS50034 would need to be checked but good to know other errors too. if(!$exists -and $errorDetails) { if($errorDetails.startsWith("AADSTS50053")) # The account is locked, you've tried to sign in too many times with an incorrect user ID or password. { $exists = $True } elseif($errorDetails.StartsWith("AADSTS50126")) # Error validating credentials due to invalid username or password. { $exists = $True } elseif($errorDetails.StartsWith("AADSTS50076")) # Due to a configuration change made by your administrator, or because you moved to a new location, you must use multi-factor authentication to access '{resource}' { $exists = $True } elseif($errorDetails.StartsWith("AADSTS700016")) # Application with identifier '{appIdentifier}' was not found in the directory '{tenantName}'. This can happen if the application has not been installed by the administrator of the tenant or consented to by any user in the tenant. You may have sent your authentication request to the wrong tenant. { $exists = $True } elseif($errorDetails.StartsWith("AADSTS50034")) # The user account {identifier} does not exist in the {tenant} directory. To sign into this application, the account must be added to the directory. { $exists = $False } elseif($errorDetails.StartsWith("AADSTS50059")) # No tenant-identifying information found in either the request or implied by any provided credentials. { $exists = $False } elseif($errorDetails.StartsWith("AADSTS81016")) # Invalid STS request. { Write-Warning "Got Invalid STS request. The tenant may not have DesktopSSO or Directory Sync enabled." Remove-Variable exists } else { # Can't be sure so return empty Remove-Variable exists } } } return $exists } } # Checks whether the tenant has MDI enabled # Mar 11th 2023 function GetMDIInstance { [cmdletbinding()] Param( [Parameter(Mandatory=$True)] [String]$Tenant ) Process { # Ref: https://learn.microsoft.com/en-us/defender-for-identity/configure-proxy#enable-access-to-defender-for-identity-service-urls-in-the-proxy-server # Ref: https://github.com/thalpius/Microsoft-Defender-for-Identity-Check-Instance # The MDI url is <instance>.atp.azure.com where instance is the tenant or tenant-onmicrosoft-com # Get the instance part if FQDN is provided if($Tenant.IndexOf(".") -ge 0) { $Tenant=$Tenant.Substring(0,$Tenant.IndexOf(".")) } Write-Verbose "Getting MDI Instance for $Tenant" $domains =@( "$tenant.atp.azure.com", "$tenant-onmicrosoft-com.atp.azure.com" ) foreach($domain in $domains) { $results=Resolve-DnsName -Name $Domain -DnsOnly -NoHostsFile -NoIdn -ErrorAction SilentlyContinue if($results) { return $domain } } return $null } } |