Detection rules › Sigma

Potential Password Spraying Attempt Using Dsacls.EXE

Status
test
Severity
medium
Log source
category process_creation, product windows
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects possible password spraying attempts using Dsacls

Known false positives

  • Legitimate use of dsacls to bind to an LDAP session

MITRE ATT&CK coverage

Telemetry coverage

ProviderRecord / event type
SysmonEvent ID 1: Process creation

Rule body

title: Potential Password Spraying Attempt Using Dsacls.EXE
id: bac9fb54-2da7-44e9-988f-11e9a5edbc0c
status: test
description: Detects possible password spraying attempts using Dsacls
references:
    - https://www.ired.team/offensive-security-experiments/active-directory-kerberos-abuse/using-dsacls-to-check-ad-object-permissions#password-spraying-anyone
    - https://ss64.com/nt/dsacls.html
    - https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/cc771151(v=ws.11)
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-06-20
modified: 2023-02-04
tags:
    - attack.stealth
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\dsacls.exe'
        - OriginalFileName: "DSACLS.EXE"
    selection_cli:
        CommandLine|contains|all:
            - '/user:'
            - '/passwd:'
    condition: all of selection*
falsepositives:
    - Legitimate use of dsacls to bind to an LDAP session
level: medium

Stages and Predicates

Stage 0: condition

all of selection*

Stage 1: selection_img

selection_img:
    - Image|endswith: '\dsacls.exe'
    - OriginalFileName: "DSACLS.EXE"

Stage 2: selection_cli

selection_cli:
    CommandLine|contains|all:
        - '/user:'
        - '/passwd:'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • /passwd:
  • /user: corpus 7 (sigma 5, splunk 2)
field:"CommandLine" kind:match
Imageends_with
  • \dsacls.exe corpus 2 (sigma 2)
field:"Image" kind:ends_with value:"\dsacls.exe"
OriginalFileNameeq
  • DSACLS.EXE corpus 2 (sigma 2)
field:"OriginalFileName" kind:eq value:"DSACLS.EXE"