Powershell Iterate through multidimensional array of hashtables to find a match and combine values from both arrays - powershell

Question

I need to combine values from 2 JSONs:
If there is a match in alerts IDs, I need to create structure, that will take data from both jsons
Result for a match should look like:
$array = #()
$hashtable = #{}
$hashtable.AlertID (does not matter what JSON is it from)
$hashtable.Tags (from JSON 1)
$hashtable.IncidentName (from JSON2)
$hashtable.IncidentID (from JSON2)
$array += $hashtable
I would prefer if this would be done with c style powershell loop.
c style for loop = for ($x = 0; $x -array.count; $x++)
JSON 1:
[
{
"Status": "Active",
"IncidentId": "3",
"tags": "SINC0008009",
"AlertId": [
"da637563185629568182_-638872186",
"da637563185631732095_1120592736",
"da637563185706412029_-614525914",
"da637563185760439486_-276692370",
"da637563185856325888_-1949235651",
"da637563186785996176_2128073884",
"da637563186789897000_1239551047",
"da637563186806513555_1512241399",
"da637563193194338043_-244132089"
],
"severity": "Medium"
},
{
"Status": "Active",
"IncidentId": "4",
"tags": "SINC0008008",
"AlertId": [
"da637643650725801726_1735022501",
"da637643650741237104_1473290917",
"da637643650748739479_-40211355",
"da637643652767933265_-1887823168",
"da637643670830160376_-443360743"
],
"severity": "Medium"
},
{
"Status": "Active",
"IncidentId": "2",
"tags": null,
"AlertId": [
"caD76232A5-F386-3C5D-94CD-7C82A7F778DC"
],
"severity": "Medium"
},
{
"Status": "Active",
"IncidentId": "1",
"tags": null,
"AlertId": [
"ca6534FF45-D62A-3FB7-BD6B-FF5029C553DB"
],
"severity": "Medium"
}
]
JSON 2:
{
"value": [
{
"incidentId": 3,
"incidentName": "Multi-stage incident involving Initial access & Discovery on one endpoint",
"status": "Active",
"severity": "Medium",
"tags": ["SINC0000001"],
"comments": [],
"alerts": [
{
"alertId": "da637563185629568182_-638872186",
"incidentId": 3,
"description": "A suspicious PowerShell activity was observed on the machine. ",
"status": "New",
"severity": "Medium",
"devices": [
{
"deviceDnsName": "xxxxx"
}
],
"entities": [
{
"entityType": "User",
"accountName": "xxxxxx",
"userPrincipalName": "xxx#xx.xx"
},
{
"entityType": "Process"
},
{
"entityType": "Process",
"verdict": "Suspicious"
},
{
"entityType": "File"
}
]
},
{
"alertId": "da637563185631732095_1120592736",
"incidentId": 3,
"devices": [
{
"osPlatform": "Windows10",
"version": "1909"
}
],
"entities": [
{
"entityType": "User",
"remediationStatus": "None"
}
]
}
]
},
{
"incidentId": 4,
"incidentName": "Multi-stage incident involving Initial access & Discovery on one endpoint",
"status": "Active",
"severity": "Medium",
"tags": ["SINC0000002"],
"comments": [],
"alerts": [
{
"alertId": "da637563185629568182_-638872186",
"incidentId": 3,
"description": "A suspicious PowerShell activity was observed on the machine. ",
"status": "New",
"severity": "Medium",
"devices": [
{
"deviceDnsName": "xxxxx"
}
],
"entities": [
{
"entityType": "User",
"accountName": "xxxxxx",
"userPrincipalName": "xxx#xx.xx"
},
{
"entityType": "Process"
},
{
"entityType": "Process",
"verdict": "Suspicious"
},
{
"entityType": "File"
}
]
},
{
"alertId": "da637563185631732095_1120592736",
"incidentId": 3,
"devices": [
{
"osPlatform": "Windows10",
"version": "1909"
}
],
"entities": [
{
"entityType": "User",
"remediationStatus": "None"
}
]
}
]
}
]
}
Till now, I was looking into using nested foreach loop to address it but it does not behave like I want. I am looking for for loop as I could use the indexes.

Answer 1

Instead of creating an array of Hashtables, I think it's better to create an array of PsCustomObjects, because outputting the result to console/file/json would be a lot easier then.
$json1 = Get-Content -Path 'X:\json1.json' -Raw | ConvertFrom-Json
$json2 = Get-Content -Path 'X:\json2.json' -Raw | ConvertFrom-Json
$result = foreach ($incident in $json1) {
foreach ($alertId in $incident.AlertId) {
$json2.value | Where-Object { $_.alerts.alertId -eq $alertId } | ForEach-Object {
# output an object with the wanted properties
[PsCustomObject]#{
AlertID = $alertId # from json1
Tags = $incident.Tags # from json1
IncidentName = $_.incidentName # from json2
IncidentID = $_.incidentId # from json2
}
}
}
}
# output on screen
$result | Format-Table -AutoSize # or use Out-GridView
# output to new JSON
$result | ConvertTo-Json
# output to CSV file
$result | Export-Csv -Path 'X:\incidents.csv' -NoTypeInformation
Using your examples, the output to console window is:
AlertID Tags IncidentName IncidentID
------- ---- ------------ ----------
da637563185629568182_-638872186 SINC0008009 Multi-stage incident involving Initial access & Discovery on one endpoint 3
da637563185629568182_-638872186 SINC0008009 Multi-stage incident involving Initial access & Discovery on one endpoint 4
da637563185631732095_1120592736 SINC0008009 Multi-stage incident involving Initial access & Discovery on one endpoint 3
da637563185631732095_1120592736 SINC0008009 Multi-stage incident involving Initial access & Discovery on one endpoint 4