Detection rules › Splunk
Suspicious ntds.dit Commands (Sysmon)
Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights. This use case detects patterns of commands associated with ntds.dit dumping and/or exfiltration
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Credential Access | T1003.003 OS Credential Dumping: NTDS |
References
- https://www.ired.team/offensive-security/credential-access-and-credential-dumping/ntds.dit-enumeration
- https://www.n00py.io/2022/03/manipulating-user-passwords-without-mimikatz/
- https://pentestlab.blog/tag/ntds-dit/
- https://github.com/zcgonvh/NTDSDumpEx
- https://blog.talosintelligence.com/2022/08/recent-cyber-attack.html?m=1
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
Rule body yaml
id: '20632.36764'
title: Suspicious ntds.dit Commands
description: 'Adversaries may attempt to access or create a copy of the Active Directory
domain database in order to steal credential information, as well as obtain other
information about domain members such as devices, users, and access rights. This
use case detects patterns of commands associated with ntds.dit dumping and/or exfiltration.
-- Threat Actor Association: UNC5221, UTA0178 -- Software Association: Akira --
Atomics T1003.003 Test #3'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "<EventID>1<")
(TERM(ntdsutil) OR TERM(ntds) OR "ntds.dit") (((TERM(ac) TERM(i)) OR (TERM(activate)
TERM(instance)) TERM(create) TERM(full)) OR TERM(copy)) | regex process="(?i)(ac\s+i\s+ntds.+create\s+full)|(copy\s+.+?ntds\.dit)|(activate\s+instance\s+ntds.*create\s+full)"
| table _time, host, user, process*, parent_process_path | bin span=1s | stats values(*)
as * by _time, host '
techniques:
- credential-access:os credential dumping:ntds
technique_id:
- T1003.003
data_category:
- Windows Sysmon
- Process command-line parameters
references:
- https://www.ired.team/offensive-security/credential-access-and-credential-dumping/ntds.dit-enumeration
- https://www.n00py.io/2022/03/manipulating-user-passwords-without-mimikatz/
- https://pentestlab.blog/tag/ntds-dit/
- https://github.com/zcgonvh/NTDSDumpEx
- https://blog.talosintelligence.com/2022/08/recent-cyber-attack.html?m=1
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "<EventID>1<") (TERM(ntdsutil) OR TERM(ntds) OR "ntds.dit") (((TERM(ac) TERM(i)) OR (TERM(activate) TERM(instance)) TERM(create) TERM(full)) OR TERM(copy))
Stage 2: regex
| regex process="(?i)(ac\s+i\s+ntds.+create\s+full)|(copy\s+.+?ntds\.dit)|(activate\s+instance\s+ntds.*create\s+full)"
Stage 3: table
| table _time, host, user, process*, parent_process_path
Stage 4: bucket
| bin span=1s
Stage 5: stats
| stats values(*) as * by _time, host
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
Search terms
Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.
| Stage | Term |
|---|---|
| 1 | TERM |
| 1 | "<EventID>1<" |
| 1 | TERM |
| 1 | ntdsutil |
| 1 | TERM |
| 1 | ntds |
| 1 | "ntds.dit" |
| 1 | TERM |
| 1 | ac |
| 1 | TERM |
| 1 | i |
| 1 | TERM |
| 1 | activate |
| 1 | TERM |
| 1 | instance |
| 1 | TERM |
| 1 | create |
| 1 | TERM |
| 1 | full |
| 1 | TERM |
| 1 | copy |