Name:Windows Finger.exe Connecting to a Remote Host id:86a5686a-7bc4-469c-9f88-2620279ede6e version:1 date:None author:Onur Mustafa Erdogan, Splunk status:production type:TTP 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. Data_source:
-Sysmon EventID 1
-Windows Event Log Security 4688
-CrowdStrike ProcessRollup2
search:| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes WHERE
( Processes.process_name="finger.exe" OR Processes.original_file_name="finger.exe" ) Processes.process="*@*"
how_to_implement: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. References: -https://packetwatch.com/resources/threat-profile/clickfix-abuses-finger-to-deliver-castleloader -https://lolbas-project.github.io/lolbas/Binaries/Finger/ drilldown_searches: name:'View the detection results for - "$dest$"' search:'%original_detection_search% | search dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'7d' latest_offset:'0' analytic_story:['Command And Control', 'Compromised Windows Host', 'Fake CAPTCHA Campaigns', 'Windows Post-Exploitation', 'Living Off The Land']
