Detection: Socat Remote TCP Connection with Local Echo Disabled

Updated Date: 2026-08-27 ID: 458c6c37-116d-4f01-8267-f09f5b82cd14 Author: Maria Jose Erquiaga, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic detects execution of the socat utility with a remote TCP or OpenSSL connection and local terminal echo disabled. This configuration may be used for interactive terminal sessions, password handling, automation, or network debugging. When observed in an unexpected context, such as execution by an unusual parent process or connection to an untrusted endpoint, it may indicate suspicious remote access 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
 8Processes.process_name="socat*"
 9Processes.process="*echo=0*"
10Processes.process IN (
11    "*openssl:*",
12    "*tcp:*",
13    "*tcp4:*",
14    "*tcp6:*"
15)
16
17by Processes.dest Processes.original_file_name Processes.parent_process_id
18   Processes.process Processes.process_exec Processes.process_guid
19   Processes.process_hash Processes.process_id
20   Processes.process_current_directory Processes.process_name
21   Processes.process_path Processes.user
22   Processes.user_id Processes.vendor_product
23
24
25| `drop_dm_object_name(Processes)`
26
27| `security_content_ctime(firstTime)`
28
29| `security_content_ctime(lastTime)`
30
31| `socat_remote_tcp_connection_with_local_echo_disabled_filter`

Data Source

Name	Platform	Sourcetype	Source
Osquery Results	Other	`'osquery:results'`	`'osquery'`
Sysmon for Linux EventID 1	Linux	`'sysmon:linux'`	`'Syslog:Linux-Sysmon/Operational'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
socat_remote_tcp_connection_with_local_echo_disabled_filter	`search *`

socat_remote_tcp_connection_with_local_echo_disabled_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
T1059	Command and Scripting Interpreter	Execution
T1572	Protocol Tunneling	Command and Control

Command and Control

Installation

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

This detection uses osquery and endpoint security on MacOS. Follow the link in references, which describes how to setup process auditing in MacOS with endpoint security and osquery. Also the TA-OSquery must be deployed across your indexers and universal forwarders in order to have the osquery data populate the data models.

Known False Positives

Developers and network engineers may use socat with local echo disabled for legitimate TCP debugging, protocol testing, terminal handling, or troubleshooting.

Associated Analytic Story

MacOS Post-Exploitation

Intermediate Findings

Message	Entity Field	Entity Type	Risk Score
Socat was executed with local terminal echo disabled and a remote TCP or OpenSSL connection via Command Line [$process$] on endpoint [$dest$] by user [$user$].	dest	system	20

Threat Objects

Field	Type
process	process

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`osquery`	`osquery:results`
Integration	✅ Passing	Dataset	`osquery`	`osquery:results`

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