Potential Recon Activity Via Nltest.EXE

Status: test
Severity: medium
Log source: product windows, category process_creation
Author: Craig Young, oscd.community, Georg Lauenstein
Source: github.com/SigmaHQ/sigma

Detects nltest commands that can be used for information discovery

MITRE ATT&CK coverage

Tactic	Techniques
Discovery	`T1016` System Network Configuration Discovery, `T1482` Domain Trust Discovery

Event coverage

Provider	Event	Title
Sysmon	Event ID 1	Process creation

Rule body yaml

title: Potential Recon Activity Via Nltest.EXE
id: 5cc90652-4cbd-4241-aa3b-4b462fa5a248
related:
    - id: 410ad193-a728-4107-bc79-4419789fcbf8
      type: similar
    - id: 903076ff-f442-475a-b667-4f246bcc203b
      type: similar
    - id: 77815820-246c-47b8-9741-e0def3f57308
      type: obsolete
status: test
description: Detects nltest commands that can be used for information discovery
references:
    - https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/cc731935(v=ws.11)
    - https://thedfirreport.com/2021/08/16/trickbot-leads-up-to-fake-1password-installation/
    - https://thedfirreport.com/2020/10/18/ryuk-in-5-hours/
    - https://book.hacktricks.xyz/windows/basic-cmd-for-pentesters
    - https://research.nccgroup.com/2022/08/19/back-in-black-unlocking-a-lockbit-3-0-ransomware-attack/
    - https://eqllib.readthedocs.io/en/latest/analytics/03e231a6-74bc-467a-acb1-e5676b0fb55e.html
    - https://redcanary.com/blog/how-one-hospital-thwarted-a-ryuk-ransomware-outbreak/
    - https://github.com/redcanaryco/atomic-red-team/blob/5360c9d9ffa3b25f6495f7a16e267b719eba2c37/atomics/T1482/T1482.md#atomic-test-2---windows---discover-domain-trusts-with-nltest
author: Craig Young, oscd.community, Georg Lauenstein
date: 2021-07-24
modified: 2023-12-15
tags:
    - attack.discovery
    - attack.t1016
    - attack.t1482
logsource:
    category: process_creation
    product: windows
detection:
    selection_nltest:
        - Image|endswith: '\nltest.exe'
        - OriginalFileName: 'nltestrk.exe'
    selection_recon:
        - CommandLine|contains|all:
              - 'server'
              - 'query'
        - CommandLine|contains:
              - '/user'
              - 'all_trusts' # Flag for /domain_trusts
              - 'dclist:'
              - 'dnsgetdc:'
              - 'domain_trusts'
              - 'dsgetdc:'
              - 'parentdomain'
              - 'trusted_domains'
    condition: all of selection_*
falsepositives:
    - Legitimate administration use but user and host must be investigated
level: medium

Stages and Predicates

Stage 0: `condition`

all of selection_*

Stage 1: `selection_nltest`

selection_nltest:
    - Image|endswith: '\nltest.exe'
    - OriginalFileName: 'nltestrk.exe'

Stage 2: `selection_recon`

selection_recon:
    - CommandLine|contains|all:
          - 'server'
          - 'query'
    - CommandLine|contains:
          - '/user'
          - 'all_trusts'
          - 'dclist:'
          - 'dnsgetdc:'
          - 'domain_trusts'
          - 'dsgetdc:'
          - 'parentdomain'
          - 'trusted_domains'

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.

Field	Kind	Values
`CommandLine`	match	`/user` `all_trusts` `dclist:` `dnsgetdc:` `domain_trusts` `dsgetdc:` `parentdomain` `query` corpus 8 (sigma 7, splunk 1) `server` `trusted_domains`
`Image`	ends_with	`\nltest.exe` corpus 9 (sigma 9)
`OriginalFileName`	eq	`nltestrk.exe` corpus 4 (sigma 2, splunk 2)

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

Potential Recon Activity Via Nltest.EXE

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection_nltest`

Stage 2: `selection_recon`

Indicators

Keyboard shortcuts

Search operators

Potential Recon Activity Via Nltest.EXE

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection_nltest

Stage 2: selection_recon

Indicators

Stage 0: `condition`

Stage 1: `selection_nltest`

Stage 2: `selection_recon`