Elastic Security Detection Rules

Netcat Listener Established via rlwrap

Last updated 5 months ago on 2025-03-20
Created 2 years ago on 2023-09-22

About

Monitors for the execution of a netcat listener via rlwrap. rlwrap is a 'readline wrapper', a small utility that uses the GNU Readline library to allow the editing of keyboard input for any command. This utility can be used in conjunction with netcat to gain a more stable reverse shell.
Tags
Domain: EndpointOS: LinuxUse Case: Threat DetectionTactic: ExecutionData Source: Elastic DefendData Source: Elastic EndgameData Source: CrowdstrikeData Source: SentinelOneLanguage: eql
Severity
low
Risk Score
21
MITRE ATT&CK™

Execution (TA0002)(opens in a new tab or window)

↳ Command and Scripting Interpreter (T1059)(opens in a new tab or window)

False Positive Examples
Netcat is a dual-use tool that can be used for benign or malicious activity. Netcat is included in some Linux distributions so its presence is not necessarily suspicious. Some normal use of this program, while uncommon, may originate from scripts, automation tools, and frameworks.
License
Elastic License v2(opens in a new tab or window)

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
endgame-*logs-crowdstrike.fdr*logs-endpoint.events.process*logs-sentinel_one_cloud_funnel.*
Related Integrations

endpoint(opens in a new tab or window)

crowdstrike(opens in a new tab or window)

sentinel_one_cloud_funnel(opens in a new tab or window)

Query
process where host.os.type == "linux" and event.type == "start" and
  event.action in ("exec", "exec_event", "start", "ProcessRollup2") and
  process.name == "rlwrap" and process.args in ("nc", "ncat", "netcat", "nc.openbsd", "socat") and
  process.args : "*l*" and process.args_count >= 4

Install detection rules in Elastic Security

Detect Netcat Listener Established via rlwrap in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).