Probable AdFind Recon Tool Usage (Normalized Process Events)

Severity: high
Time window: 1h
Author: Yuval Naor
Source: github.com/Azure/Azure-Sentinel

Identifies the host and account that executed AdFind by hash and filename in addition to common and unique flags that are used by many threat actors in discovery. To use this analytics rule, make sure you have deployed the ASIM normalization parsers

MITRE ATT&CK coverage

Tactic	Techniques
Discovery	`T1018` Remote System Discovery

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation
Sysmon	Event ID 5: Process terminated
Security-Auditing	Event ID 4688: A new process has been created.
Security-Auditing	Event ID 4689: A process has exited.

Rule body

id: 45076281-35ae-45e0-b443-c32aa0baf965
name: Probable AdFind Recon Tool Usage (Normalized Process Events)
description: |
  'Identifies the host and account that executed AdFind by hash and filename in addition to common and unique flags that are used by many threat actors in discovery.
  To use this analytics rule, make sure you have deployed the [ASIM normalization parsers](https://aka.ms/ASimProcessEvent)'
severity: High
requiredDataConnectors: []
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Discovery
relevantTechniques:
  - T1018
tags:
  - Id: c63ae777-d5e0-4113-8c9a-c2c9d3d09fcd
    version: 1.0.0
  - Schema: ASIMProcessEvent
    SchemaVersion: 0.1.0

query: |
  let args = dynamic(["objectcategory","domainlist","dcmodes","adinfo","trustdmp","computers_pwdnotreqd","Domain Admins", "objectcategory=person", "objectcategory=computer", "objectcategory=*","dclist"]);
  let parentProcesses = dynamic(["pwsh.exe","powershell.exe","cmd.exe"]);
  imProcessCreate
  //looks for execution from a shell
  | where ActingProcessName has_any (parentProcesses)
  | extend ActingProcessFileName = tostring(split(ActingProcessName, '\\')[-1])
  | where ActingProcessFileName in~ (parentProcesses)
  // main filter
  | where Process hassuffix "AdFind.exe" or TargetProcessSHA256 == "c92c158d7c37fea795114fa6491fe5f145ad2f8c08776b18ae79db811e8e36a3"
  // AdFind common Flags to check for from various threat actor TTPs
  or CommandLine has_any (args)
  | extend AlgorithmType = "SHA256"
  | extend AccountName = tostring(split(User, @'\')[1]), AccountNTDomain = tostring(split(User, @'\')[0])
  | extend HostName = tostring(split(Dvc, ".")[0]), DomainIndex = toint(indexof(Dvc, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(Dvc, DomainIndex + 1), Dvc)
  | project-away DomainIndex
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: User
      - identifier: Name
        columnName: AccountName
      - identifier: NTDomain
        columnName: AccountNTDomain
  - entityType: Host
    fieldMappings:
      - identifier: FullName
        columnName: Dvc
      - identifier: HostName
        columnName: HostName
      - identifier: DnsDomain
        columnName: HostNameDomain
  - entityType: Process
    fieldMappings:
      - identifier: ProcessId
        columnName: ActingProcessName
      - identifier: CommandLine
        columnName: CommandLine
  - entityType: FileHash
    fieldMappings:
      - identifier: Algorithm
        columnName: AlgorithmType
      - identifier: Value
        columnName: TargetProcessSHA256
version: 1.1.6
kind: Scheduled
metadata:
    source:
        kind: Community
    author:
        name: Yuval Naor
    support:
        tier: Community
    categories:
        domains: [ "Security - Threat Intelligence" ]

Stages and Predicates

Parameters

let parentProcesses = dynamic(["pwsh.exe","powershell.exe","cmd.exe"]);

Let binding: `args` used in Stage 5

let args = dynamic(["objectcategory","domainlist","dcmodes","adinfo","trustdmp","computers_pwdnotreqd","Domain Admins", "objectcategory=person", "objectcategory=computer", "objectcategory=*","dclist"]);

Stage 1: `source`

imProcessCreate

Stage 2: `where`

| where ActingProcessName has_any (parentProcesses)

Stage 3: `extend`

| extend ActingProcessFileName = tostring(split(ActingProcessName, '\\')[-1])

Stage 4: `where`

| where ActingProcessFileName in~ (parentProcesses)

Stage 5: `where`

| where Process hassuffix "AdFind.exe" or TargetProcessSHA256 == "c92c158d7c37fea795114fa6491fe5f145ad2f8c08776b18ae79db811e8e36a3"
or CommandLine has_any (args)

Stage 6: `extend` (4 consecutive steps)

| extend AlgorithmType = "SHA256"
| extend AccountName = tostring(split(User, @'\')[1]), AccountNTDomain = tostring(split(User, @'\')[0])
| extend HostName = tostring(split(Dvc, ".")[0]), DomainIndex = toint(indexof(Dvc, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Dvc, DomainIndex + 1), Dvc)

Stage 7: `project-away`

| project-away DomainIndex

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`ActingProcessFileName`	in	`cmd.exe` `powershell.exe` `pwsh.exe`	`field:"ActingProcessFileName" kind:in`
`ActingProcessName`	match	`cmd.exe` transforms: `term` `powershell.exe` transforms: `term` `pwsh.exe` transforms: `term`	`field:"ParentImage" kind:match`
`CommandLine`	match	`Domain Admins` transforms: `term` corpus 5 (sigma 2, kusto 2, splunk 1) `adinfo` transforms: `term` corpus 4 (sigma 2, kusto 2) `computers_pwdnotreqd` transforms: `term` corpus 4 (sigma 2, kusto 2) `dclist` transforms: `term` corpus 2 (kusto 2) `dcmodes` transforms: `term` corpus 4 (sigma 2, kusto 2) `domainlist` transforms: `term` corpus 4 (sigma 2, kusto 2) `objectcategory` transforms: `term` corpus 2 (kusto 2) `objectcategory=*` transforms: `term` corpus 2 (kusto 2) `objectcategory=computer` transforms: `term` corpus 2 (kusto 2) `objectcategory=person` transforms: `term` corpus 2 (kusto 2) `trustdmp` transforms: `term` corpus 4 (sigma 2, kusto 2)	`field:"CommandLine" kind:match`
`Process`	ends_with	`AdFind.exe`	`field:"Process" kind:ends_with value:"AdFind.exe"`
`TargetProcessSHA256`	eq	`c92c158d7c37fea795114fa6491fe5f145ad2f8c08776b18ae79db811e8e36a3` corpus 2 (kusto 2)	`field:"sha256" kind:eq value:"c92c158d7c37fea795114fa6491fe5f145ad2f8c08776b18ae79db811e8e36a3"`

Output fields

These fields are emitted when the rule matches.

Field	Source
`ActingProcessFileName`	`extend`
`AlgorithmType`	`extend`
`AccountNTDomain`	`extend`
`AccountName`	`extend`
`HostName`	`extend`
`HostNameDomain`	`extend`

Probable AdFind Recon Tool Usage (Normalized Process Events)

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Parameters

Let binding: args used in Stage 5

Stage 1: source

Stage 2: where

Stage 3: extend

Stage 4: where

Stage 5: where

Stage 6: extend (4 consecutive steps)

Stage 7: project-away