Detection rules › Elastic
Segfault Detected
Monitors kernel logs for segfault messages. A segfault, or segmentation fault, is an error that occurs when a program tries to access a memory location that it's not allowed to access, typically leading to program termination. A segfault can be an indication of malicious behavior if it results from attempts to exploit buffer overflows or other vulnerabilities in software to execute arbitrary code or disrupt its normal operation.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | T1203 Exploitation for Client Execution |
Rule body elastic
[metadata]
bypass_bbr_timing = true
creation_date = "2023/10/26"
integration = ["system"]
maturity = "production"
updated_date = "2026/03/24"
[rule]
author = ["Elastic"]
building_block_type = "default"
description = """
Monitors kernel logs for segfault messages. A segfault, or segmentation fault, is an error that occurs when a program
tries to access a memory location that it's not allowed to access, typically leading to program termination. A segfault
can be an indication of malicious behavior if it results from attempts to exploit buffer overflows or other
vulnerabilities in software to execute arbitrary code or disrupt its normal operation.
"""
from = "now-9m"
index = ["logs-system.syslog-*"]
language = "kuery"
license = "Elastic License v2"
name = "Segfault Detected"
risk_score = 21
rule_id = "5c81fc9d-1eae-437f-ba07-268472967013"
setup = """## Setup
This rule requires data coming in from one of the following integrations:
- Filebeat
### Filebeat Setup
Filebeat is a lightweight shipper for forwarding and centralizing log data. Installed as an agent on your servers, Filebeat monitors the log files or locations that you specify, collects log events, and forwards them either to Elasticsearch or Logstash for indexing.
#### The following steps should be executed in order to add the Filebeat for the Linux System:
- Elastic provides repositories available for APT and YUM-based distributions. Note that we provide binary packages, but no source packages.
- To install the APT and YUM repositories follow the setup instructions in this [helper guide](https://www.elastic.co/guide/en/beats/filebeat/current/setup-repositories.html).
- To run Filebeat on Docker follow the setup instructions in the [helper guide](https://www.elastic.co/guide/en/beats/filebeat/current/running-on-docker.html).
- To run Filebeat on Kubernetes follow the setup instructions in the [helper guide](https://www.elastic.co/guide/en/beats/filebeat/current/running-on-kubernetes.html).
- For quick start information for Filebeat refer to the [helper guide](https://www.elastic.co/guide/en/beats/filebeat/8.11/filebeat-installation-configuration.html).
- For complete Setup and Run Filebeat information refer to the [helper guide](https://www.elastic.co/guide/en/beats/filebeat/current/setting-up-and-running.html).
#### Rule Specific Setup Note
- This rule requires the Filebeat System Module to be enabled.
- The system module collects and parses logs created by the system logging service of common Unix/Linux based distributions.
- To run the system module of Filebeat on Linux follow the setup instructions in the [helper guide](https://www.elastic.co/guide/en/beats/filebeat/current/filebeat-module-system.html).
"""
severity = "low"
tags = ["Domain: Endpoint", "OS: Linux", "Use Case: Threat Detection", "Tactic: Execution", "Rule Type: BBR"]
timestamp_override = "event.ingested"
type = "query"
query = '''
host.os.type:linux and event.dataset:"system.syslog" and process.name:kernel and message:segfault
'''
[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1203"
name = "Exploitation for Client Execution"
reference = "https://attack.mitre.org/techniques/T1203/"
[rule.threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"
Stages and Predicates
Stage 1: query
host.os.type:linux and event.dataset:"system.syslog" and process.name:kernel and message:segfault
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
event.dataset | eq |
|
message | eq |
|
process.name | eq |
|