Hunt for public facing devices and exposed ports over time

Group by: DeviceName, InternetFacingLocalIp, InternetFacingLocalPort, InternetFacingTransportProtocol
Author: Robbe Van den Daele
Source: github.com/HybridBrothers/Hunting-Queries-Detection-Rules

Find public facing devices over time via the public device tag in the DeviceInfo table.

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1190` Exploit Public-Facing Application

References

https://hybridbrothers.com/analyzing-mde-network-inspections/

Rule body yaml

// Create a base function
let base = (){ 
    DeviceInfo
    | where Timestamp > ago(30d)
    | extend AdditionalFields = todynamic(AdditionalFields)
    | extend InternetFacingLastSeen = todatetime(AdditionalFields.InternetFacingLastSeen)
        , InternetFacingReason = tostring(AdditionalFields.InternetFacingReason)
        , InternetFacingLocalIp = tostring(AdditionalFields.InternetFacingLocalIp)
        , InternetFacingPublicScannedIp = tostring(AdditionalFields.InternetFacingPublicScannedIp)
        , InternetFacingLocalPort = tostring(AdditionalFields.InternetFacingLocalPort)
        , InternetFacingPublicScannedPort = tostring(AdditionalFields.InternetFacingPublicScannedPort)
        , InternetFacingTransportProtocol = tostring(AdditionalFields.InternetFacingTransportProtocol)
};
base()
// Get the latest resport
| summarize arg_max(InternetFacingLastSeen, *) by DeviceName, InternetFacingLocalIp, InternetFacingLocalPort, InternetFacingTransportProtocol
// Join with the earliest report
| join kind=inner ( base()
    | summarize arg_min(InternetFacingLastSeen, *) by DeviceName, InternetFacingLocalIp, InternetFacingLocalPort, InternetFacingTransportProtocol
) on DeviceName, InternetFacingLocalIp, InternetFacingLocalPort, InternetFacingTransportProtocol
// Make a data point for each day between earliest and latest report
| extend Range = range(bin(InternetFacingLastSeen1, 1d), bin(InternetFacingLastSeen, 1d), 1d)
// Now expand all datapoints for dates the ports have been active
| mv-expand Range
| where Range != ""
| summarize count() by InternetFacingLocalPort, bin(todatetime(Range), 1d)
| render linechart

Stages and Predicates

Let binding: `base`

let base = (){ 
    DeviceInfo
    | where Timestamp > ago(30d)
    | extend AdditionalFields = todynamic(AdditionalFields)
    | extend InternetFacingLastSeen = todatetime(AdditionalFields.InternetFacingLastSeen)
        , InternetFacingReason = tostring(AdditionalFields.InternetFacingReason)
        , InternetFacingLocalIp = tostring(AdditionalFields.InternetFacingLocalIp)
        , InternetFacingPublicScannedIp = tostring(AdditionalFields.InternetFacingPublicScannedIp)
        , InternetFacingLocalPort = tostring(AdditionalFields.InternetFacingLocalPort)
        , InternetFacingPublicScannedPort = tostring(AdditionalFields.InternetFacingPublicScannedPort)
        , InternetFacingTransportProtocol = tostring(AdditionalFields.InternetFacingTransportProtocol)
};

Stage 1: `source`

DeviceInfo

Stage 2: `where`

where ...

Stage 3: `extend`

extend AdditionalFields

Stage 4: `extend`

extend InternetFacingLastSeen, InternetFacingLocalIp, InternetFacingLocalPort, InternetFacingPublicScannedIp, InternetFacingPublicScannedPort, InternetFacingReason, InternetFacingTransportProtocol

Stage 5: `summarize`

summarize by DeviceName, InternetFacingLocalIp, InternetFacingLocalPort, InternetFacingTransportProtocol

Stage 6: `join`

join kind=inner (...)

Stage 7: `extend`

extend Range

Stage 8: `mv-expand`

mv-expand Range

Stage 9: `where`

where Range !~ ""

Stage 10: `summarize`

summarize by InternetFacingLocalPort

Stage 11: `render`

render

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field	Source
`InternetFacingLocalPort`	`summarize`

`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)

Hunt for public facing devices and exposed ports over time

MITRE ATT&CK coverage

References

Rule body yaml

Stages and Predicates

Let binding: `base`

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Stage 4: `extend`

Stage 5: `summarize`

Stage 6: `join`

Stage 7: `extend`

Stage 8: `mv-expand`

Stage 9: `where`

Stage 10: `summarize`

Stage 11: `render`

Output fields

Keyboard shortcuts

Search operators

Hunt for public facing devices and exposed ports over time

MITRE ATT&CK coverage

References

Rule body yaml

Stages and Predicates

Let binding: base

Stage 1: source

Stage 2: where

Stage 3: extend

Stage 4: extend

Stage 5: summarize

Stage 6: join

Stage 7: extend

Stage 8: mv-expand

Stage 9: where

Stage 10: summarize

Stage 11: render

Output fields

Let binding: `base`

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Stage 4: `extend`

Stage 5: `summarize`

Stage 6: `join`

Stage 7: `extend`

Stage 8: `mv-expand`

Stage 9: `where`

Stage 10: `summarize`

Stage 11: `render`