Match Legitimate Name or Location - 2

Back


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

triggerOperator: gt
relevantTechniques:
- T1036.005
tactics:
- DefenseEvasion
triggerThreshold: 0
status: Available
id: dd22dc4f-ab7c-4d0a-84ad-cc393638ba31
requiredDataConnectors:
- connectorId: MicrosoftThreatProtection
  dataTypes:
  - DeviceProcessEvents
name: Match Legitimate Name or Location - 2
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/FalconFriday/Analytic Rules/MatchLegitimateNameOrLocation.yaml
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.  
version: 1.0.1
kind: Scheduled
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))  
entityMappings:
- entityType: Host
  fieldMappings:
  - identifier: FullName
    columnName: DeviceName
- entityType: Account
  fieldMappings:
  - identifier: Sid
    columnName: AccountSid
  - identifier: Name
    columnName: AccountName
  - identifier: NTDomain
    columnName: AccountDomain
- entityType: Process
  fieldMappings:
  - identifier: CommandLine
    columnName: ProcessCommandLine
severity: Medium
queryFrequency: 1h
queryPeriod: 1h

ARM