Detection rules › Splunk

Ollama Abnormal Network Connectivity

Status
experimental
Severity
low
Group by
attack_type, host, incidents, last_incident, severity, src, warning_messages
Author
Rod Soto
Source
github.com/splunk/security_content

Detects abnormal network activity and connectivity issues in Ollama including non-localhost API access attempts and warning-level network errors such as DNS lookup failures, TCP connection issues, or host resolution problems that may indicate network-based attacks, unauthorized access attempts, or infrastructure reconnaissance activity.

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.

MITRE ATT&CK coverage

TacticTechniques
Command & Control

Rule body

name: Ollama Abnormal Network Connectivity
id: 19ec30ad-faa2-496a-a6a9-f2e5f778fbdb
version: 5
creation_date: '2025-10-13'
modification_date: '2026-05-13'
author: Rod Soto
status: experimental
type: Anomaly
description: Detects abnormal network activity and connectivity issues in Ollama including non-localhost API access attempts and warning-level network errors such as DNS lookup failures, TCP connection issues, or host resolution problems that may indicate network-based attacks, unauthorized access attempts, or infrastructure reconnaissance activity.
data_source:
    - Ollama Server
search: |-
    `ollama_server` level=WARN (msg="*failed*" OR msg="*dial tcp*" OR msg="*lookup*" OR msg="*no such host*" OR msg="*connection*" OR msg="*network*" OR msg="*timeout*" OR msg="*unreachable*" OR msg="*refused*")
      | eval src=coalesce(src, src_ip, "N/A")
      | stats count as incidents, values(src) as src, values(msg) as warning_messages, latest(_time) as last_incident
        BY host
      | eval last_incident=strftime(last_incident, "%Y-%m-%d %H:%M:%S")
      | eval severity="medium"
      | eval attack_type="Abnormal Network Connectivity"
      | stats count
        BY last_incident, host, incidents,
           src, warning_messages, severity,
           attack_type
      | `ollama_abnormal_network_connectivity_filter`
how_to_implement: '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.
references:
    - https://github.com/rosplk/ta-ollama
intermediate_findings:
    entities:
        - field: host
          type: system
          score: 20
          message: 'Abnormal network activity detected on $host$ with $incidents$ incidents from $src$. Investigation needed for network errors: $warning_messages$.'
threat_objects:
    - field: src
      type: system
analytic_story:
    - Suspicious Ollama Activities
asset_type: Web Application
mitre_attack_id:
    - T1571
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: application
security_domain: endpoint

Stages and Predicates

Stage 1: search

`ollama_server` level=WARN (msg="*failed*" OR msg="*dial tcp*" OR msg="*lookup*" OR msg="*no such host*" OR msg="*connection*" OR msg="*network*" OR msg="*timeout*" OR msg="*unreachable*" OR msg="*refused*")

Stage 2: eval

| eval src=coalesce(src, src_ip, "N/A")

Stage 3: stats

| stats count as incidents, values(src) as src, values(msg) as warning_messages, latest(_time) as last_incident
    BY host

Stage 4: eval

| eval last_incident=strftime(last_incident, "%Y-%m-%d %H:%M:%S")

Stage 5: eval

| eval severity="medium"

Stage 6: eval

| eval attack_type="Abnormal Network Connectivity"

Stage 7: stats

| stats count
    BY last_incident, host, incidents,
       src, warning_messages, severity,
       attack_type

Stage 8: search

| `ollama_abnormal_network_connectivity_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
leveleq
  • WARN
field:"level" kind:eq value:"WARN"
msgeq
  • "*connection*"
  • "*dial tcp*"
  • "*failed*"
  • "*lookup*"
  • "*network*"
  • "*no such host*"
  • "*refused*"
  • "*timeout*"
  • "*unreachable*"
field:"msg" kind:eq
sourcetypeeq
  • ollama:server
field:"sourcetype" kind:eq value:"ollama:server"