Active Directory Structure Export Via Csvde.EXE

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

Detects the execution of "csvde.exe" in order to export organizational Active Directory structure.

MITRE ATT&CK coverage

Tactic	Techniques
Discovery	`T1087.002` Account Discovery: Domain Account

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation

Rule body

title: Active Directory Structure Export Via Csvde.EXE
id: e5d36acd-acb4-4c6f-a13f-9eb203d50099
status: test
description: Detects the execution of "csvde.exe" in order to export organizational Active Directory structure.
references:
    - https://www.cybereason.com/blog/research/operation-ghostshell-novel-rat-targets-global-aerospace-and-telecoms-firms
    - https://web.archive.org/web/20180725233601/https://www.pwc.co.uk/cyber-security/pdf/cloud-hopper-annex-b-final.pdf
    - https://businessinsights.bitdefender.com/deep-dive-into-a-backdoordiplomacy-attack-a-study-of-an-attackers-toolkit
    - https://redcanary.com/blog/msix-installers/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-03-14
tags:
    - attack.exfiltration
    - attack.discovery
    - attack.t1087.002
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\csvde.exe'
        - OriginalFileName: 'csvde.exe'
    selection_remote:
        CommandLine|contains: ' -f'
    filter_import:
        CommandLine|contains: ' -i'
    condition: all of selection_* and not 1 of filter_*
falsepositives:
    - Unknown
level: medium

Stages and Predicates

Stage 0: `condition`

all of selection_* and not 1 of filter_*

Stage 1: `selection_img`

selection_img:
    - Image|endswith: '\csvde.exe'
    - OriginalFileName: 'csvde.exe'

Stage 2: `selection_remote`

selection_remote:
    CommandLine|contains: ' -f'

Stage 3: `not filter_import`

filter_import:
    CommandLine|contains: ' -i'

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`CommandLine`	match	`-i`	`excludes:CommandLine` `field:"CommandLine" value:" -i"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	match	`-f` corpus 4 (sigma 3, chronicle 1)	`field:"CommandLine" kind:match value:" -f"`
`Image`	ends_with	`\csvde.exe`	`field:"Image" kind:ends_with value:"\csvde.exe"`
`OriginalFileName`	eq	`csvde.exe`	`field:"OriginalFileName" kind:eq value:"csvde.exe"`

Active Directory Structure Export Via Csvde.EXE

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection_img

Stage 2: selection_remote

Stage 3: not filter_import

Exclusions

Indicators

Stage 0: `condition`

Stage 1: `selection_img`

Stage 2: `selection_remote`

Stage 3: `not filter_import`