Detection: Linux Suspicious Child Process of PostgreSQL

Description

The following analytic detects PostgreSQL spawning a shell, interpreter, or network utility as a child process. When an attacker exploits a remote code execution vulnerability in PostgreSQL (such as via malicious COPY TO/FROM PROGRAM, CVE-2019-9193, or an insecurely configured extension), the database process itself becomes the parent of attacker-controlled commands. Legitimate PostgreSQL processes do not normally fork shells or download tools, making this a high-fidelity signal for post-exploitation activity.

Search

 1
 2| tstats `security_content_summariesonly`
 3  count min(_time) as firstTime
 4        max(_time) as lastTime
 5
 6FROM datamodel=Endpoint.Processes WHERE
 7
 8(
 9    Processes.parent_process_name IN (
10        "postgres",
11        "postmaster",
12        "pg_ctl"
13    )
14    OR
15    Processes.parent_process_path = "*/bin/postgres"
16    OR
17    Processes.process_current_directory="*/var/lib/postgresql/*/main*"
18)
19Processes.process_name IN (
20    "awk", "bash", "curl", "dash", "env", "gawk", "id", "ifconfig",
21    "ksh", "lua", "nc", "ncat", "netcat", "nmap", "openssl", "perl",
22    "php", "python", "python2", "python3", "ruby", "sh", "socat",
23    "tcpdump", "wget", "whoami", "zsh"
24)
25
26BY Processes.action Processes.dest Processes.original_file_name
27   Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
28   Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
29   Processes.process Processes.process_current_directory Processes.process_exec
30   Processes.process_guid Processes.process_hash Processes.process_id
31   Processes.process_integrity_level Processes.process_name Processes.process_path
32   Processes.user Processes.user_id Processes.vendor_product
33
34| `drop_dm_object_name(Processes)`
35
36| `security_content_ctime(firstTime)`
37
38| `security_content_ctime(lastTime)`
39
40| `linux_suspicious_child_process_of_postgresql_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon for Linux EventID 1	Linux	'sysmon:linux'	'Syslog:Linux-Sysmon/Operational'

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

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

Custom PostgreSQL extensions or wrapper scripts that legitimately invoke shell utilities may trigger this detection. Baseline the environment and use the filter macro to suppress known-good parent/child combinations. Recommend throttling by dest and process_name before enabling broadly.

Associated Analytic Story

• Compromised Linux Host

• Linux Post-Exploitation

• Linux Privilege Escalation

• Linux Persistence Techniques

• SQL Injection

Finding

Threat Objects

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-9193

• https://www.horizon3.ai/cve-2023-27524-insecure-default-configuration-in-apache-superset-leads-to-remote-code-execution/

• https://www.postgresql.org/docs/current/sql-copy.html

Detection Testing

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: 1