Detection rules › Kusto
Caramel Tsunami Actor IOC - July 2021
Identifies a match across IOC's related to an actor tracked by Microsoft as Caramel Tsunami
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1546 Event Triggered Execution |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body kusto
id: 066395ac-ef91-4993-8bf6-25c61ab0ca5a
name: Caramel Tsunami Actor IOC - July 2021
description: |
'Identifies a match across IOC's related to an actor tracked by Microsoft as Caramel Tsunami'
severity: High
status: Available
requiredDataConnectors:
- connectorId: WindowsForwardedEvents
dataTypes:
- WindowsEvent
queryFrequency: 6h
queryPeriod: 6h
triggerOperator: gt
triggerThreshold: 0
tactics:
- Persistence
relevantTechniques:
- T1546
tags:
- Caramel Tsunami
query: |
let iocs = externaldata(DateAdded:string,IoC:string,Type:string,TLP:string) [@"https://raw.githubusercontent.com/Azure/Azure-Sentinel/master/Sample%20Data/Feeds/SOURGUM.csv"] with (format="csv", ignoreFirstRecord=True);
let file_path1 = (iocs | where Type =~ "filepath1" | project IoC);
let file_path2 = (iocs | where Type =~ "filepath2" | project IoC);
let file_path3 = (iocs | where Type =~ "filepath3" | project IoC);
let reg_key = (iocs | where Type =~ "regkey" | project IoC);
WindowsEvent
| where EventID == 4688 and (EventData has_any (file_path1) or EventData has_any (file_path2) or EventData has_any (file_path3) or EventData has_any ('reg add') or EventData has_any (reg_key) )
| extend CommandLine = tostring(EventData.CommandLine)
| extend NewProcessName = tostring(EventData.NewProcessName)
| extend ParentProcessName = tostring(EventData.ParentProcessName)
| where (CommandLine has_any (file_path1)) or
(CommandLine has_any (file_path3)) or
(CommandLine has 'reg add' and CommandLine has_any (reg_key) and CommandLine has_any (file_path2)) or
(NewProcessName has_any (file_path1)) or
(NewProcessName has_any (file_path3)) or
(ParentProcessName has_any (file_path1)) or
(ParentProcessName has_any (file_path3))
| extend Account = strcat(EventData.SubjectDomainName,"\\", EventData.SubjectUserName)
| extend NewProcessId = tostring(EventData.NewProcessId)
| extend IP = tostring(EventData.IpAddress)
| project TimeGenerated, Computer, NewProcessName, ParentProcessName, Account, NewProcessId, Type, IP
| extend Alert = 'SOURGUM IOC detected'
| extend AccountName = tostring(split(Account, @'\')[1]), AccountNTDomain = tostring(split(Account, @'\')[0])
| extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
entityMappings:
- entityType: Account
fieldMappings:
- identifier: FullName
columnName: Account
- identifier: Name
columnName: AccountName
- identifier: NTDomain
columnName: AccountNTDomain
- entityType: Host
fieldMappings:
- identifier: FullName
columnName: Computer
- identifier: HostName
columnName: HostName
- identifier: DnsDomain
columnName: HostNameDomain
- entityType: IP
fieldMappings:
- identifier: Address
columnName: IP
- entityType: Process
fieldMappings:
- identifier: ProcessId
columnName: NewProcessId
version: 1.0.4
kind: Scheduled
Stages and Predicates
Let binding: iocs
let iocs = externaldata(DateAdded:string,IoC:string,Type:string,TLP:string) [@"https://raw.githubusercontent.com/Azure/Azure-Sentinel/master/Sample%20Data/Feeds/SOURGUM.csv"] with (format="csv", ignoreFirstRecord=True);
Let binding: file_path1
let file_path1 = (iocs | where Type =~ "filepath1" | project IoC);
Derived from iocs.
Let binding: file_path2
let file_path2 = (iocs | where Type =~ "filepath2" | project IoC);
Derived from iocs.
Let binding: file_path3
let file_path3 = (iocs | where Type =~ "filepath3" | project IoC);
Derived from iocs.
Let binding: reg_key
let reg_key = (iocs | where Type =~ "regkey" | project IoC);
Derived from iocs.
Stage 1: source
WindowsEvent
Stage 2: where
| where EventID == 4688 and (EventData has_any (file_path1) or EventData has_any (file_path2) or EventData has_any (file_path3) or EventData has_any ('reg add') or EventData has_any (reg_key) )
References file_path1, file_path2, file_path3, reg_key (defined above).
Stage 3: extend (3 consecutive steps)
| extend CommandLine = tostring(EventData.CommandLine)
| extend NewProcessName = tostring(EventData.NewProcessName)
| extend ParentProcessName = tostring(EventData.ParentProcessName)
Stage 4: where
| where (CommandLine has_any (file_path1)) or
(CommandLine has_any (file_path3)) or
(CommandLine has 'reg add' and CommandLine has_any (reg_key) and CommandLine has_any (file_path2)) or
(NewProcessName has_any (file_path1)) or
(NewProcessName has_any (file_path3)) or
(ParentProcessName has_any (file_path1)) or
(ParentProcessName has_any (file_path3))
References file_path1, file_path2, file_path3, reg_key (defined above).
Stage 5: extend (3 consecutive steps)
| extend Account = strcat(EventData.SubjectDomainName,"\\", EventData.SubjectUserName)
| extend NewProcessId = tostring(EventData.NewProcessId)
| extend IP = tostring(EventData.IpAddress)
Stage 6: project
| project TimeGenerated, Computer, NewProcessName, ParentProcessName, Account, NewProcessId, Type, IP
Stage 7: extend (4 consecutive steps)
| extend Alert = 'SOURGUM IOC detected'
| extend AccountName = tostring(split(Account, @'\')[1]), AccountNTDomain = tostring(split(Account, @'\')[0])
| extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
CommandLine | match |
|
EventData | match |
|
EventID | eq |
|
NewProcessName | match |
|
ParentProcessName | match |
|
Output fields
Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.
| Field | Source |
|---|---|
Account | project |
Computer | project |
IP | project |
NewProcessId | project |
NewProcessName | project |
ParentProcessName | project |
TimeGenerated | project |
Type | project |
Alert | extend |
AccountNTDomain | extend |
AccountName | extend |
DomainIndex | extend |
HostName | extend |
HostNameDomain | extend |