System Network Connections Discovery

Status: production
Kind: building block (feeds higher-level correlation rules; not a standalone alert)
Severity: low
Time window: 119m
Group by: host.id, process.command_line, process.parent.executable
Author: Elastic
Source: github.com/elastic/detection-rules

Adversaries may attempt to get a listing of network connections to or from a compromised system.

MITRE ATT&CK coverage

Tactic	Techniques
Discovery	`T1016` System Network Configuration Discovery, `T1049` System Network Connections Discovery

Rule body elastic

[metadata]
creation_date = "2023/07/11"
integration = ["endpoint"]
maturity = "production"
updated_date = "2026/03/24"

[rule]
author = ["Elastic"]
building_block_type = "default"
description = """
Adversaries may attempt to get a listing of network connections to or from a compromised system.
"""
from = "now-119m"
index = ["logs-endpoint.events.*"]
interval = "60m"
language = "kuery"
license = "Elastic License v2"
name = "System Network Connections Discovery"
risk_score = 21
rule_id = "e2dc8f8c-5f16-42fa-b49e-0eb8057f7444"
severity = "low"
tags = [
    "Domain: Endpoint",
    "OS: Linux",
    "OS: macOS",
    "Use Case: Threat Detection",
    "Tactic: Discovery",
    "Rule Type: BBR",
    "Data Source: Elastic Defend",
]
timestamp_override = "event.ingested"
type = "new_terms"
query = '''
event.category:process and host.os.type:(linux or macos) and event.type:start and event.action:exec and
process.name:("netstat" or "lsof" or "ss" or "iftop" or "ip" or "nmcli" or "arp" or "route" or "ifconfig" or "netcfg" or "networksetup") and
not (
  process.parent.executable:(
    /Library/Elastic/Agent/* or "/Applications/Docker.app/Contents/MacOS/com.docker.backend" or
    "/opt/NinjaRMMAgent/programfiles/ninjarmm-linagent" or "/usr/local/ASR/Vx/bin/svagents"
  ) or
  process.working_directory:("/var/ossec" or "/usr/lib/check_mk_agent/plugins" or "/opt/microsoft/mdatp/sbin")
)
'''

[[rule.threat]]
framework = "MITRE ATT&CK"

[[rule.threat.technique]]
id = "T1016"
name = "System Network Configuration Discovery"
reference = "https://attack.mitre.org/techniques/T1016/"

[[rule.threat.technique]]
id = "T1049"
name = "System Network Connections Discovery"
reference = "https://attack.mitre.org/techniques/T1049/"

[rule.threat.tactic]
id = "TA0007"
name = "Discovery"
reference = "https://attack.mitre.org/tactics/TA0007/"
[rule.new_terms]
field = "new_terms_fields"
value = ["process.parent.executable", "process.command_line", "host.id"]

[[rule.new_terms.history_window_start]]
field = "history_window_start"
value = "now-5d"

Stages and Predicates

Stage 1: `new_terms`

event.category:process and host.os.type:(linux or macos) and event.type:start and event.action:exec and
process.name:("netstat" or "lsof" or "ss" or "iftop" or "ip" or "nmcli" or "arp" or "route" or "ifconfig" or "netcfg" or "networksetup") and
not (
  process.parent.executable:(
    /Library/Elastic/Agent/* or "/Applications/Docker.app/Contents/MacOS/com.docker.backend" or
    "/opt/NinjaRMMAgent/programfiles/ninjarmm-linagent" or "/usr/local/ASR/Vx/bin/svagents"
  ) or
  process.working_directory:("/var/ossec" or "/usr/lib/check_mk_agent/plugins" or "/opt/microsoft/mdatp/sbin")
)

New terms: process.parent.executable, process.command_line, host.id
History since: now-5d

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`process.parent.executable`	eq	`/Applications/Docker.app/Contents/MacOS/com.docker.backend`
`process.parent.executable`	eq	`/opt/NinjaRMMAgent/programfiles/ninjarmm-linagent`
`process.parent.executable`	eq	`/usr/local/ASR/Vx/bin/svagents`
`process.parent.executable`	starts_with	`/Library/Elastic/Agent/`
`process.working_directory`	in	`/opt/microsoft/mdatp/sbin`, `/usr/lib/check_mk_agent/plugins`, `/var/ossec`

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
`event.action`	eq	`exec`
`event.category`	eq	`process`
`event.type`	eq	`start`
`process.name`	in	`arp` `ifconfig` `iftop` `ip` `lsof` `netcfg` `netstat` `networksetup` `nmcli` `route` `ss`

`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)

System Network Connections Discovery

MITRE ATT&CK coverage

Rule body elastic

Stages and Predicates

Stage 1: `new_terms`

Exclusions

Indicators

Keyboard shortcuts

Search operators

System Network Connections Discovery

MITRE ATT&CK coverage

Rule body elastic

Stages and Predicates

Stage 1: new_terms

Exclusions

Indicators

Stage 1: `new_terms`