Solutions/Threat Intelligence (NEW)/Analytic Rules/IPEntity_VMConnection.yaml (61 lines of code) (raw):

id: aed70d71-adb2-4f73-becd-02150b13950b name: TI Map IP Entity to VMConnection description: | This query maps any IP indicators of compromise (IOCs) from threat intelligence (TI), by searching for matches in VMConnection. severity: Medium requiredDataConnectors: - connectorId: ThreatIntelligence dataTypes: - ThreatIntelligenceIndicator - connectorId: ThreatIntelligenceTaxii dataTypes: - ThreatIntelligenceIndicator - connectorId: MicrosoftDefenderThreatIntelligence dataTypes: - ThreatIntelligenceIndicator - connectorId: AzureMonitor(VMInsights) dataTypes: - VMConnection queryFrequency: 1h queryPeriod: 14d triggerOperator: gt triggerThreshold: 0 tactics: - CommandAndControl relevantTechniques: - T1071 query: | let dt_lookBack = 1h; // Look back 1 hour for VMConnection events let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators // Fetch threat intelligence indicators related to IP addresses let IP_Indicators = ThreatIntelIndicators //extract key part of kv pair | extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0))) | where isnotempty(IndicatorType) and IndicatorType == "ipv4-addr" | extend NetworkSourceIP = toupper(ObservableValue) | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel) | where isnotempty(NetworkSourceIP) | where TimeGenerated >= ago(ioc_lookBack) | extend TI_ipEntity = iff(isnotempty(NetworkSourceIP), NetworkSourceIP, NetworkSourceIP) | extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity) | extend Url = iff(ObservableKey == "url:value", ObservableValue, "") | where ipv4_is_private(TI_ipEntity) == false and TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127." | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id | where IsActive == true and ValidUntil > now(); // Perform a join between IP indicators and VMConnection events IP_Indicators | project-reorder *, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, TI_ipEntity // Use innerunique to keep performance fast and result set low, as we only need one match to indicate potential malicious activity that needs investigation | join kind=innerunique ( VMConnection | where TimeGenerated >= ago(dt_lookBack) | extend VMConnection_TimeGenerated = TimeGenerated ) on $left.TI_ipEntity == $right.RemoteIp // Filter out VMConnection events that occurred after the expiration of the corresponding indicator | where VMConnection_TimeGenerated < ValidUntil // Group the results by IndicatorId and keep the VMConnection event with the latest timestamp | summarize VMConnection_TimeGenerated = arg_max(VMConnection_TimeGenerated, *) by Id, RemoteIp // Select the desired output fields | extend Description = tostring(parse_json(Data).description) | extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels)) | project VMConnection_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence, TI_ipEntity, Computer, Direction, ProcessName, SourceIp, DestinationIp, RemoteIp, Protocol, DestinationPort, NetworkSourceIP, Type, Url | extend timestamp = VMConnection_TimeGenerated, HostName = tostring(split(Computer, '.', 0)[0]), DnsDomain = tostring(strcat_array(array_slice(split(Computer, '.'), 1, -1), '.')) entityMappings: - entityType: Host fieldMappings: - identifier: HostName columnName: HostName - identifier: DnsDomain columnName: DnsDomain - entityType: IP fieldMappings: - identifier: Address columnName: RemoteIp - entityType: URL fieldMappings: - identifier: Url columnName: Url version: 1.4.4 kind: Scheduled