Potential Shell via Wildcard Injection Detected

This rule monitors for the execution of a set of linux binaries, that are potentially vulnerable to wildcard injection, with suspicious command line flags followed by a shell spawn event. Linux wildcard injection is a type of security vulnerability where attackers manipulate commands or input containing wildcards (e.g., *, ?, []) to execute unintended operations or access sensitive data by tricking the system into interpreting the wildcard characters in unexpected ways.

Rule type: eql

Rule indices:

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:

Tags:

Version: 4

Rule authors:

Rule license: Elastic License v2

sequence by host.id with maxspan=1s
  [process where host.os.type == "linux" and event.action == "exec" and event.type == "start" and (
    (process.name == "tar" and process.args : "--checkpoint=*" and process.args : "--checkpoint-action=*") or
    (process.name == "rsync" and process.args : "-e*") or
    (process.name == "zip" and process.args == "--unzip-command") )]  by process.entity_id
  [process where host.os.type == "linux" and event.action == "exec" and event.type == "start" and
     process.parent.name : ("tar", "rsync", "zip") and
     process.name : ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish")] by process.parent.entity_id