Detection rules › Sigma
Ruby Inline Command Execution
Detects execution of ruby using the "-e" flag. This is could be used as a way to launch a reverse shell or execute live ruby code.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
Rule body
title: Ruby Inline Command Execution
id: 20a5ffa1-3848-4584-b6f8-c7c7fd9f69c8
status: test
description: Detects execution of ruby using the "-e" flag. This is could be used as a way to launch a reverse shell or execute live ruby code.
references:
- https://pentestmonkey.net/cheat-sheet/shells/reverse-shell-cheat-sheet
- https://www.revshells.com/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-01-02
tags:
- attack.execution
- attack.t1059
logsource:
category: process_creation
product: windows
detection:
selection_img:
- Image|endswith: '\ruby.exe'
- OriginalFileName: 'ruby.exe'
selection_cli:
CommandLine|contains: ' -e'
condition: all of selection_*
falsepositives:
- Unknown
level: medium
Stages and Predicates
Stage 0: condition
all of selection_*Stage 1: selection_img
selection_img:
- Image|endswith: '\ruby.exe'
- OriginalFileName: 'ruby.exe'
Stage 2: selection_cli
selection_cli:
CommandLine|contains: ' -e'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
CommandLine | match |
| field:"CommandLine" kind:match value:" -e" |
Image | ends_with |
| field:"Image" kind:ends_with value:"\ruby.exe" |
OriginalFileName | eq |
| field:"OriginalFileName" kind:eq value:"ruby.exe" |