Detection rules › Kusto
TI Map IP entity to OfficeActivity
This query maps any IP indicators of compromise (IOCs) from threat intelligence (TI), by searching for matches in OfficeActivity.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Command & Control |
Rule body
id: f50280e5-5eb1-4e95-99fd-9d584a987bdd
name: TI Map IP entity to OfficeActivity
description: |
This query maps any IP indicators of compromise (IOCs) from threat intelligence (TI), by searching for matches in OfficeActivity.
severity: Medium
requiredDataConnectors:
- connectorId: ThreatIntelligence
dataTypes:
- ThreatIntelIndicators
- connectorId: ThreatIntelligenceTaxii
dataTypes:
- ThreatIntelIndicators
- connectorId: MicrosoftDefenderThreatIntelligence
dataTypes:
- ThreatIntelIndicators
- connectorId: Office365
dataTypes:
- OfficeActivity
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
- CommandAndControl
relevantTechniques:
- T1071
query: |
let dt_lookBack = 1h; // Look back 1 hour for OfficeActivity events
let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators
let OfficeActivity_ = materialize(OfficeActivity
| where isnotempty(ClientIP)
| where TimeGenerated >= ago(dt_lookBack)
| extend ClientIPValues = extract_all(@'\[?(::ffff:)?(?P<IPAddress>(\d+\.\d+\.\d+\.\d+)|[^\]%]+)(%\d+)?\]?([-:](?P<Port>\d+))?', dynamic(["IPAddress", "Port"]), ClientIP)[0]
| extend IPAddress = iff(array_length(ClientIPValues) > 0, tostring(ClientIPValues[0]), '')
| project-rename OfficeActivity_TimeGenerated = TimeGenerated);
let ActivityIPs = OfficeActivity_ | summarize IPs = make_list(IPAddress);
// Fetch threat intelligence indicators related to IP addresses
let IP_Indicators = materialize(ThreatIntelIndicators
//extract key part of kv pair
| extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
| where IndicatorType in ("ipv4-addr", "ipv6-addr", "network-traffic")
| extend NetworkSourceIP = toupper(ObservableValue)
| extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
| where TimeGenerated >= ago(ioc_lookBack)
| extend TI_ipEntity = NetworkSourceIP
| where TI_ipEntity in (ActivityIPs)
| extend Url = iff(ObservableKey == "url:value", ObservableValue, "")
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
| where IsActive and (ValidUntil > now() or isempty(ValidUntil))
| extend Description = tostring(parse_json(Data).description)
| where Description !contains_cs "State: inactive;" and Description !contains_cs "State: falsepos;");
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 (OfficeActivity_)
on $left.TI_ipEntity == $right.IPAddress
// Filter out OfficeActivity events that occurred after the expiration of the corresponding indicator
| where OfficeActivity_TimeGenerated < ValidUntil
// Group the results by IndicatorId and keep the OfficeActivity event with the latest timestamp
| summarize OfficeActivity_TimeGenerated = arg_max(OfficeActivity_TimeGenerated, *) by Id
// Select the desired output fields
| extend Description = tostring(parse_json(Data).description)
| extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
| project OfficeActivity_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence, TI_ipEntity, ClientIP, UserId, Operation, ResultStatus, RecordType, OfficeObjectId, NetworkSourceIP, Type, Url
| extend timestamp = OfficeActivity_TimeGenerated, Name = tostring(split(UserId, '@', 0)[0]), UPNSuffix = tostring(split(UserId, '@', 1)[0])
entityMappings:
- entityType: Account
fieldMappings:
- identifier: FullName
columnName: UserId
- identifier: Name
columnName: Name
- identifier: UPNSuffix
columnName: UPNSuffix
- entityType: IP
fieldMappings:
- identifier: Address
columnName: TI_ipEntity
- entityType: URL
fieldMappings:
- identifier: Url
columnName: Url
version: 1.4.8
kind: Scheduled
Stages and Predicates
Parameters
let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let IP_Indicators is inlined into the numbered stages below.
Let binding: OfficeActivity_
let OfficeActivity_ = materialize(OfficeActivity
| where isnotempty(ClientIP)
| where TimeGenerated >= ago(dt_lookBack)
| extend ClientIPValues = extract_all(@'\[?(::ffff:)?(?P<IPAddress>(\d+\.\d+\.\d+\.\d+)|[^\]%]+)(%\d+)?\]?([-:](?P<Port>\d+))?', dynamic(["IPAddress", "Port"]), ClientIP)[0]
| extend IPAddress = iff(array_length(ClientIPValues) > 0, tostring(ClientIPValues[0]), '')
| project-rename OfficeActivity_TimeGenerated = TimeGenerated);
Let binding: ActivityIPs
let ActivityIPs = OfficeActivity_ | summarize IPs = make_list(IPAddress);
Stages 1 to 13 define let IP_Indicators (the rule's main pipeline source); stages 14 to 21 run on it.
Stage 1: source
ThreatIntelIndicators
Stage 2: extend
| extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
Stage 3: where
| where IndicatorType in ("ipv4-addr", "ipv6-addr", "network-traffic")
Stage 4: extend
| extend NetworkSourceIP = toupper(ObservableValue)
Stage 5: extend
| extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
Stage 6: where
| where TimeGenerated >= ago(ioc_lookBack)
Stage 7: extend
| extend TI_ipEntity = NetworkSourceIP
Stage 8: where
| where TI_ipEntity in (ActivityIPs)
Stage 9: extend
| extend Url = iff(ObservableKey == "url:value", ObservableValue, "")
Url =if
ObservableKey == "url:value"ObservableValueelse
""Stage 10: summarize
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
Stage 11: where
| where IsActive and (ValidUntil > now() or isempty(ValidUntil))
Stage 12: extend
| extend Description = tostring(parse_json(Data).description)
Stage 13: where
| where Description !contains_cs "State: inactive;" and Description !contains_cs "State: falsepos;"
Stage 14: project-reorder
IP_Indicators
| project-reorder *, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, TI_ipEntity
Stage 15: join
| join kind=innerunique (OfficeActivity_)
on $left.TI_ipEntity == $right.IPAddress
Stage 16: where
| where OfficeActivity_TimeGenerated < ValidUntil
Stage 17: summarize
| summarize OfficeActivity_TimeGenerated = arg_max(OfficeActivity_TimeGenerated, *) by Id
Stage 18: extend
| extend Description = tostring(parse_json(Data).description)
Stage 19: extend
| extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
Stage 20: project
| project OfficeActivity_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence, TI_ipEntity, ClientIP, UserId, Operation, ResultStatus, RecordType, OfficeObjectId, NetworkSourceIP, Type, Url
Stage 21: extend
| extend timestamp = OfficeActivity_TimeGenerated, Name = tostring(split(UserId, '@', 0)[0]), UPNSuffix = tostring(split(UserId, '@', 1)[0])
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
Description | contains | State: falsepos; | excludes:Description field:"Description" value:"State: falsepos;" |
Description | contains | State: inactive; | excludes:Description field:"Description" value:"State: inactive;" |
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
ClientIP | is_not_null | field:"ClientIP" kind:is_not_null | |
IndicatorType | in |
| field:"IndicatorType" kind:in |
OfficeActivity_TimeGenerated | cross_field_compare |
| field:"m365::TimeGenerated" kind:cross_field_compare value:"ValidUntil" |
TI_ipEntity | in |
| field:"TI_ipEntity" kind:in value:"ActivityIPs" |
ValidUntil | is_null | field:"ValidUntil" kind:is_null |
Output fields
These fields are emitted when the rule matches.
| Field | Source |
|---|---|
ActivityGroupNames | project |
ClientIP | project |
Confidence | project |
Description | project |
Id | project |
NetworkSourceIP | project |
OfficeActivity_TimeGenerated | project |
OfficeObjectId | project |
Operation | project |
RecordType | project |
ResultStatus | project |
TI_ipEntity | project |
Type | project |
Url | project |
UserId | project |
ValidUntil | project |
Name | extend |
UPNSuffix | extend |
timestamp | extend |