Detection rules › Sigma
Interactive Bash Suspicious Children
Detects suspicious interactive bash as a parent to rather uncommon child processes
Known false positives
- Legitimate software that uses these patterns
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | |
| Stealth |
Telemetry coverage
| Platform | Record / event type |
|---|---|
| Linux | Event ID 1: Process Create |
Rule body
title: Interactive Bash Suspicious Children
id: ea3ecad2-db86-4a89-ad0b-132a10d2db55
status: test
description: Detects suspicious interactive bash as a parent to rather uncommon child processes
references:
- Internal Research
author: Florian Roth (Nextron Systems)
date: 2022-03-14
tags:
- attack.execution
- attack.stealth
- attack.t1059.004
- attack.t1036
logsource:
product: linux
category: process_creation
detection:
selection:
ParentCommandLine: 'bash -i'
anomaly1:
CommandLine|contains:
- '-c import '
- 'base64'
- 'pty.spawn'
anomaly2:
Image|endswith:
- 'whoami'
- 'iptables'
- '/ncat'
- '/nc'
- '/netcat'
condition: selection and 1 of anomaly*
falsepositives:
- Legitimate software that uses these patterns
level: medium
Stages and Predicates
Stage 0: condition
selection and 1 of anomaly*Stage 1: selection
selection:
ParentCommandLine: 'bash -i'
Stage 2: anomaly1
anomaly1:
CommandLine|contains:
- '-c import '
- 'base64'
- 'pty.spawn'
Stage 3: anomaly2
anomaly2:
Image|endswith:
- 'whoami'
- 'iptables'
- '/ncat'
- '/nc'
- '/netcat'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
CommandLine | match |
| field:"CommandLine" kind:match |
Image | ends_with |
| field:"Image" kind:ends_with |
ParentCommandLine | eq |
| field:"ParentCommandLine" kind:eq value:"bash -i" |