Detection: Windows Finger.exe Connecting to a Remote Host

Updated Date: 2026-09-16 ID: 86a5686a-7bc4-469c-9f88-2620279ede6e Author: Onur Mustafa Erdogan, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic identifies the finger.exe utility being spawned with a command line containing an @ character, indicating a remote host/server was specified. The Finger protocol utility is largely obsolete in modern environments and has been abused by adversaries as a living-off-the-land binary (LOLBIN) to retrieve encoded payloads or establish covert command-and-control communication with an attacker-controlled finger server. This behavior is uncommon in legitimate enterprise usage and warrants investigation.

Search

 1
 2| tstats `security_content_summariesonly`
 3  count min(_time) as firstTime
 4        max(_time) as lastTime
 5FROM datamodel=Endpoint.Processes WHERE
 6
 7(
 8    Processes.process_name="finger.exe"
 9    OR
10    Processes.original_file_name="finger.exe"
11)
12Processes.process="*@*"
13
14by Processes.action Processes.dest Processes.original_file_name
15   Processes.parent_process Processes.parent_process_exec
16   Processes.parent_process_guid Processes.parent_process_id
17   Processes.parent_process_name Processes.parent_process_path
18   Processes.process Processes.process_exec Processes.process_guid
19   Processes.process_hash Processes.process_id
20   Processes.process_integrity_level Processes.process_name
21   Processes.process_path Processes.user Processes.user_id
22   Processes.vendor_product
23
24
25| `drop_dm_object_name(Processes)`
26
27| `security_content_ctime(firstTime)`
28
29| `security_content_ctime(lastTime)`
30
31| `windows_finger_exe_connecting_to_a_remote_host_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 1	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`
CrowdStrike ProcessRollup2	Other	`'crowdstrike:events:sensor'`	`'crowdstrike'`
Windows Event Log Security 4688	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Security'`

Macros Used

Name	Value
security_content_summariesonly	`summariesonly=`summariesonly_config `allow_old_summaries=`oldsummaries_config `fillnull_value=`fillnull_config``
windows_finger_exe_connecting_to_a_remote_host_filter	`search *`

windows_finger_exe_connecting_to_a_remote_host_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1071	Application Layer Protocol	Command and Control

Command and Control

DE.CM

CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Finding (Notable)	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Intermediate Finding (Risk Event)	No

TTP detections generate a Finding (Notable) and may generate Intermediate Findings (Risk Events) for associated entities.

Implementation

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

No false positives have been identified at this time.

Associated Analytic Story

Finding

Title	Entity Field	Entity Type	Risk Score
The [$process_path$] utility was used to connect to a remote host via the Command Line [$process$] from [$dest$]	dest	system	50

Threat Objects

Field	Type
process	process

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-Sysmon/Operational`	`XmlWinEventLog`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub |

Version: 1