URL Added to Application from Unknown Domain

Original query, unchanged.

let domains =
  SigninLogs
  | where ResultType == 0
  | extend domain = split(UserPrincipalName, "@")[1]
  | extend domain = tostring(split(UserPrincipalName, "@")[1])
  | summarize by tolower(tostring(domain));
  AuditLogs
  | where Category =~ "ApplicationManagement"
  | where Result =~ "success"
  | where OperationName =~ 'Update Application'
  | mv-expand TargetResources
  | mv-expand TargetResources.modifiedProperties
  | where TargetResources_modifiedProperties.displayName =~ "AppAddress"
  | extend Key = tostring(TargetResources_modifiedProperties.displayName)
  | extend NewValue = TargetResources_modifiedProperties.newValue
  | extend OldValue = TargetResources_modifiedProperties.oldValue
  | where isnotempty(Key) and isnotempty(NewValue)
  | project-reorder Key, NewValue, OldValue
  | extend NewUrls = extract_all('"Address":([^,]*)', tostring(NewValue))
  | extend OldUrls = extract_all('"Address":([^,]*)', tostring(OldValue))
  | extend AddedUrls = set_difference(NewUrls, OldUrls)
  | where array_length(AddedUrls) > 0
  | extend UserAgent = iif(tostring(AdditionalDetails[0].key) == "User-Agent", tostring(AdditionalDetails[0].value), "")
  | extend InitiatingAppName = tostring(InitiatedBy.app.displayName)
  | extend InitiatingAppServicePrincipalId = tostring(InitiatedBy.app.servicePrincipalId)
  | extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)
  | extend InitiatingAadUserId = tostring(InitiatedBy.user.id)
  | extend InitiatingIPAddress = tostring(InitiatedBy.user.ipAddress)
  | extend InitiatedBy = tostring(iff(isnotempty(InitiatingUserPrincipalName),InitiatingUserPrincipalName, InitiatingAppName))
  | extend AppDisplayName = tostring(TargetResources.displayName)
  | where isnotempty(AddedUrls)
  | mv-expand AddedUrls
  | extend AddedUrls = trim(@'"', tostring(AddedUrls))
  | extend Domain = extract("^(?:https?:\\/\\/)?(?:[^@\\/\\n]+@)?(?:www\\.)?([^:\\/?\\n]+)/", 1, replace_string(tolower(AddedUrls), '"', ""))
  | where isnotempty(Domain)
  | extend Domain = strcat(split(Domain, ".")[-2], ".", split(Domain, ".")[-1])
  | where Domain !in (domains)
  | project-reorder TimeGenerated, AppDisplayName, AddedUrls, InitiatedBy, UserAgent, InitiatingIPAddress
  | extend InitiatingAccountName = tostring(split(InitiatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(InitiatingUserPrincipalName, "@")[1])