Potential Reverse Shell via Background Processedit

Monitors for the execution of background processes with process arguments capable of opening a socket in the /dev/tcp channel. This may indicate the creation of a backdoor reverse connection, and should be investigated further.

Rule type: eql

Rule indices:

  • logs-endpoint.events.*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References: None

Tags:

  • Domain: Endpoint
  • OS: Linux
  • Use Case: Threat Detection
  • Tactic: Execution
  • Data Source: Elastic Defend

Version: 3

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule queryedit

process where host.os.type == "linux" and event.action == "exec" and event.type == "start" and
process.name in ("setsid", "nohup") and process.args : "*/dev/tcp/*0>&1*" and
process.parent.name in ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish")

Framework: MITRE ATT&CKTM