Detection: Ollama Abnormal Network Connectivity

Created: 2025-10-13 Last Updated: 2026-10-19 ID: 19ec30ad-faa2-496a-a6a9-f2e5f778fbdb Author: Rod Soto, Nasreddine Bencherchali, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

Detects repeated Ollama warning-level network errors, such as DNS lookup failures, TCP connection issues, or host resolution problems. These events can indicate a connectivity issue and warrant investigation, but do not by themselves establish unauthorized access or reconnaissance.

Search

 1`ollama_server`
 2level=WARN
 3msg IN (
 4    "*connection*",
 5    "*dial tcp*",
 6    "*failed*",
 7    "*lookup*",
 8    "*network*",
 9    "*no such host*",
10    "*refused*",
11    "*timeout*",
12    "*unreachable*"
13)
14
15
16| eval dest=coalesce(dest, host)
17
18| bin _time span=5m
19
20| stats count as incidents
21        values(msg) as warning_messages
22        latest(_time) as last_incident
23  by _time dest
24
25
26| where incidents > 3
27
28
29| eval last_incident=strftime(last_incident, "%Y-%m-%d %H:%M:%S")
30
31
32| eval severity="medium"
33
34
35| eval attack_type="Abnormal Network Connectivity"
36
37
38| table last_incident dest incidents warning_messages severity attack_type
39
40
41| `ollama_abnormal_network_connectivity_filter`

Data Source

Name	Platform	Sourcetype	Source
Ollama Server	Other	`'ollama:server'`	`'server.log'`

Macros Used

Name	Value
ollama_server	`(sourcetype="ollama:server")`
ollama_abnormal_network_connectivity_filter	`search *`

ollama_abnormal_network_connectivity_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

DE.AE

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)	No
Creates Intermediate Finding (Risk Event)	Yes

Anomaly detections generate Intermediate Findings (Risk Events). They do not generate a Finding (Notable) directly.

Implementation

Ingest Ollama logs via Splunk TA-ollama add-on by configuring file monitoring inputs pointed to your Ollama server log directories (sourcetype: ollama:server), or enable HTTP Event Collector (HEC) for real-time API telemetry and prompt analytics (sourcetypes: ollama:api, ollama:prompts). CIM compatibility using the Web datamodel for standardized security detections.

Known False Positives

Legitimate remote access from authorized users or applications connecting from non-localhost addresses, temporary network infrastructure issues causing DNS resolution failures, firewall or network configuration changes resulting in connection timeouts, cloud-hosted Ollama instances receiving valid external API requests, or intermittent connectivity problems during network maintenance may trigger this detection during normal operations.

Associated Analytic Story

Suspicious Ollama Activities

Intermediate Findings

Message	Entity Field	Entity Type	Risk Score
Abnormal network activity on [$dest$] with [$incidents$] matching warnings [$warning_messages$]. Investigate DNS and network reachability.	dest	system	20

References

https://github.com/rosplk/ta-ollama

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`app.log`	`ollama:server`
Integration	✅ Passing	Dataset	`app.log`	`ollama:server`

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: 6