/
ThreatConnect_EmailEntity_OfficeActivity.yaml
66 lines (66 loc) · 2.62 KB
/
ThreatConnect_EmailEntity_OfficeActivity.yaml
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
id: 4f7ade3e-7121-5274-83ea-d7ed22a01fea
name: ThreatConnect TI map Email entity to OfficeActivity
version: 1.2.4
kind: Scheduled
description: |
'Identifies a match in OfficeActivity table from any Email IOC from ThreatConnect TI'
severity: Medium
requiredDataConnectors:
- connectorId: Office365
dataTypes:
- OfficeActivity
- connectorId: ThreatIntelligence
dataTypes:
- ThreatIntelligenceIndicator
- connectorId: ThreatIntelligenceTaxii
dataTypes:
- ThreatIntelligenceIndicator
- connectorId: MicrosoftDefenderThreatIntelligence
dataTypes:
- ThreatIntelligenceIndicator
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
- Impact
query: |
let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let emailregex = @'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$';
ThreatIntelligenceIndicator
| where TimeGenerated >= ago(ioc_lookBack)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where ExpirationDateTime > now() and Active == true
// Filter out non ThreatConnect TI Sources
| where SourceSystem startswith "ThreatConnect-"
//Filtering the table for Email related IOCs
| where isnotempty(EmailSenderAddress)
// using innerunique to keep perf fast and result set low, we only need one match to indicate potential malicious activity that needs to be investigated
| join kind=innerunique (
OfficeActivity | where TimeGenerated >= ago(dt_lookBack) and isnotempty(UserId)
| where UserId matches regex emailregex
| extend OfficeActivity_TimeGenerated = TimeGenerated
)
on $left.EmailSenderAddress == $right.UserId
| where OfficeActivity_TimeGenerated < ExpirationDateTime
| summarize OfficeActivity_TimeGenerated = arg_max(OfficeActivity_TimeGenerated, *) by IndicatorId, UserId
| project OfficeActivity_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,
EmailSenderName, EmailRecipient, EmailSourceDomain, EmailSourceIpAddress, EmailSubject, FileHashValue, FileHashType, UserId, ClientIP, Operation, UserType, RecordType, OfficeWorkload, Parameters
| extend Name = tostring(split(UserId, '@', 0)[0]), UPNSuffix = tostring(split(UserId, '@', 1)[0])
| extend timestamp = OfficeActivity_TimeGenerated
entityMappings:
- entityType: Account
fieldMappings:
- identifier: Name
columnName: Name
- identifier: UPNSuffix
columnName: UPNSuffix
- entityType: IP
fieldMappings:
- identifier: Address
columnName: ClientIP
- entityType: URL
fieldMappings:
- identifier: Url
columnName: Url