ID | Technique | Tactic |
---|---|---|
T1499 | Endpoint Denial of Service | Impact |
Detection: Splunk ES DoS Through Investigation Attachments
Description
The following analytic detects attempts to perform a denial of service (DoS) attack through investigation attachments in Splunk Enterprise Security (ES) versions below 7.1.2. It leverages internal Splunk logs, specifically monitoring the splunkd_investigation_rest_handler
for error statuses related to investigation objects. This activity is significant because it can render the Investigation feature inaccessible, disrupting incident response and forensic analysis. If confirmed malicious, this attack could prevent security teams from effectively managing and investigating security incidents, leading to prolonged exposure and potential data breaches.
Search
1`splunkd_investigation_rest_handler` status=error object=investigation
2| stats min(_time) as firstTime max(_time) as lastTime values(status) as status values(msg) as msg values(id) as investigation_id by user
3| `security_content_ctime(firstTime)`
4| `security_content_ctime(lastTime)`
5| `splunk_es_dos_through_investigation_attachments_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
Splunk | Splunk | 'splunkd_ui_access' |
'splunkd_ui_access.log' |
N/A |
Macros Used
Name | Value |
---|---|
security_content_ctime | convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$) |
splunk_es_dos_through_investigation_attachments_filter | search * |
splunk_es_dos_through_investigation_attachments_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
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 Notable | Yes |
Rule Title | %name% |
Rule Description | %description% |
Notable Event Fields | user, dest |
Creates Risk Event | True |
Implementation
This search requires access to internal indexes, only affects Enterprise Security versions below 7.1.2.
Known False Positives
This search will show the exact DoS event via error message and investigation id. The error however does not point exactly at the uploader as any users associated with the investigation will be affected. Operator must investigate using investigation id the possible origin of the malicious upload. Attack only affects specific investigation not the investigation manager.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
Denial of Service detected at Splunk ES affecting $user$ | 100 | 100 | 100 |
References
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | /opt/splunk/var/log/splunk/investigation_handler.log |
investigation_rest_handler |
Integration | ✅ Passing | Dataset | /opt/splunk/var/log/splunk/investigation_handler.log |
investigation_rest_handler |
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: 2