Match Legitimate Name or Location - 2

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Id	dd22dc4f-ab7c-4d0a-84ad-cc393638ba31
Rulename	Match Legitimate Name or Location - 2
Description	Attackers often match or approximate the name or location of legitimate files to avoid detection rules that are based trust of on certain operating system processes. This query detects mismatches in the parent-child relationship of core operating system processes to uncover different masquerading attempts.
Severity	Medium
Tactics	DefenseEvasion
Techniques	T1036.005
Required data connectors	MicrosoftThreatProtection
Kind	Scheduled
Query frequency	1h
Query period	1h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/FalconFriday/Analytic Rules/MatchLegitimateNameOrLocation.yaml
Version	1.0.1
Arm template	dd22dc4f-ab7c-4d0a-84ad-cc393638ba31.json

KQL

let ProcessRelations=datatable(ImageFile:string,ExpectedParent:dynamic) [
  "smss.exe", dynamic(["smss.exe", "ntoskrnl.exe", ""]),
  "crmss.exe", dynamic(["smss.exe"]),
  "wininit.exe", dynamic(["smss.exe"]),
  "winlogon.exe", dynamic(["smss.exe"]),
  "services.exe", dynamic(["wininit.exe"]),
  "lsaiso.exe", dynamic(["wininit.exe"]),
  "lsass.exe", dynamic(["wininit.exe"]),
  "spoolsv.exe", dynamic(["services.exe"]),
  "dllhost.exe", dynamic(["svchost.exe", "services.exe"]),
  "lsm.exe", dynamic(["wininit.exe"]),
  "svchost.exe", dynamic(["services.exe", "msmpeng.exe"]),
  "runtimebroker.exe", dynamic(["svchost.exe"]),
  "taskhostw.exe", dynamic(["svchost.exe"]),
  "userinit.exe", dynamic(["winlogon.exe"])
  // Explorer can have a lot of parents in some environments
  //,"explorer.exe", dynamic(["userinit.exe"])
];
DeviceProcessEvents
| extend ImageFile = tostring(tolower(parse_path(tostring(FolderPath)).Filename))
| extend ParentFile = tostring(tolower(parse_path(tostring(InitiatingProcessFolderPath)).Filename))
| lookup kind=inner ProcessRelations on ImageFile
| where not(set_has_element(ExpectedParent,ParentFile))

YAML

relevantTechniques:
- T1036.005
entityMappings:
- fieldMappings:
  - columnName: DeviceName
    identifier: FullName
  entityType: Host
- fieldMappings:
  - columnName: AccountSid
    identifier: Sid
  - columnName: AccountName
    identifier: Name
  - columnName: AccountDomain
    identifier: NTDomain
  entityType: Account
- fieldMappings:
  - columnName: ProcessCommandLine
    identifier: CommandLine
  entityType: Process
triggerThreshold: 0
description: |
  Attackers often match or approximate the name or location of legitimate files to avoid detection rules that are based trust of on certain operating system processes.
  This query detects mismatches in the parent-child relationship of core operating system processes to uncover different masquerading attempts.  
requiredDataConnectors:
- connectorId: MicrosoftThreatProtection
  dataTypes:
  - DeviceProcessEvents
triggerOperator: gt
version: 1.0.1
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/FalconFriday/Analytic Rules/MatchLegitimateNameOrLocation.yaml
id: dd22dc4f-ab7c-4d0a-84ad-cc393638ba31
queryFrequency: 1h
query: |
  let ProcessRelations=datatable(ImageFile:string,ExpectedParent:dynamic) [
    "smss.exe", dynamic(["smss.exe", "ntoskrnl.exe", ""]),
    "crmss.exe", dynamic(["smss.exe"]),
    "wininit.exe", dynamic(["smss.exe"]),
    "winlogon.exe", dynamic(["smss.exe"]),
    "services.exe", dynamic(["wininit.exe"]),
    "lsaiso.exe", dynamic(["wininit.exe"]),
    "lsass.exe", dynamic(["wininit.exe"]),
    "spoolsv.exe", dynamic(["services.exe"]),
    "dllhost.exe", dynamic(["svchost.exe", "services.exe"]),
    "lsm.exe", dynamic(["wininit.exe"]),
    "svchost.exe", dynamic(["services.exe", "msmpeng.exe"]),
    "runtimebroker.exe", dynamic(["svchost.exe"]),
    "taskhostw.exe", dynamic(["svchost.exe"]),
    "userinit.exe", dynamic(["winlogon.exe"])
    // Explorer can have a lot of parents in some environments
    //,"explorer.exe", dynamic(["userinit.exe"])
  ];
  DeviceProcessEvents
  | extend ImageFile = tostring(tolower(parse_path(tostring(FolderPath)).Filename))
  | extend ParentFile = tostring(tolower(parse_path(tostring(InitiatingProcessFolderPath)).Filename))
  | lookup kind=inner ProcessRelations on ImageFile
  | where not(set_has_element(ExpectedParent,ParentFile))  
severity: Medium
status: Available
queryPeriod: 1h
name: Match Legitimate Name or Location - 2
tactics:
- DefenseEvasion
kind: Scheduled

ARM