Detection rules › Sigma
Python Initiated Connection
Detects a Python process initiating a network connection. While this often relates to package installation, it can also indicate a potential malicious script communicating with a C&C server.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Discovery | T1046 Network Service Discovery |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 3 | Network connection |
Rule body yaml
title: Python Initiated Connection
id: bef0bc5a-b9ae-425d-85c6-7b2d705980c6
status: test
description: Detects a Python process initiating a network connection. While this often relates to package installation, it can also indicate a potential malicious script communicating with a C&C server.
references:
- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1046/T1046.md#atomic-test-4---port-scan-using-python
- https://pypi.org/project/scapy/
author: frack113
date: 2021-12-10
modified: 2025-03-05
tags:
- attack.discovery
- attack.t1046
logsource:
category: network_connection
product: windows
definition: 'Requirements: Field enrichment is required for the filters to work. As field such as CommandLine and ParentImage are not available by default on this event type'
detection:
selection:
Initiated: 'true'
Image|contains|all:
- '\python'
- '.exe'
filter_optional_conda:
# Related to anaconda updates. Command example: "conda update conda"
# This filter will only work with aurora agent enriched data as Sysmon EID 3 doesn't contain CommandLine nor ParentImage
ParentImage: C:\ProgramData\Anaconda3\Scripts\conda.exe
CommandLine|contains|all:
- ':\ProgramData\Anaconda3\Scripts\conda-script.py'
- 'update'
filter_optional_conda_jupyter_notebook:
# Related to anaconda opening an instance of Jupyter Notebook
# This filter will only work with aurora agent enriched data as Sysmon EID 3 doesn't contain CommandLine nor ParentImage
ParentImage: C:\ProgramData\Anaconda3\python.exe
CommandLine|contains: 'C:\ProgramData\Anaconda3\Scripts\jupyter-notebook-script.py'
filter_main_local_communication:
# This could be caused when launching an instance of Jupyter Notebook locally for example but can also be caused by other instances of python opening sockets locally etc. So comment this out if you want to monitor for those instances
DestinationIp: 127.0.0.1
SourceIp: 127.0.0.1
filter_main_pip:
CommandLine|contains|all:
- 'pip.exe'
- 'install'
condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
- Legitimate python scripts using the socket library or similar will trigger this. Apply additional filters and perform an initial baseline before deploying.
level: medium
Stages and Predicates
Stage 0: condition
selection and not 1 of filter_main_* and not 1 of filter_optional_*Stage 1: selection
selection:
Initiated: 'true'
Image|contains|all:
- '\python'
- '.exe'
Stage 2: not filter_main_*
filter_main_local_communication:
DestinationIp: 127.0.0.1
SourceIp: 127.0.0.1
filter_main_pip:
CommandLine|contains|all:
- 'pip.exe'
- 'install'
Stage 3: not filter_optional_*
filter_optional_conda:
ParentImage: C:\ProgramData\Anaconda3\Scripts\conda.exe
CommandLine|contains|all:
- ':\ProgramData\Anaconda3\Scripts\conda-script.py'
- 'update'
filter_optional_conda_jupyter_notebook:
ParentImage: C:\ProgramData\Anaconda3\python.exe
CommandLine|contains: 'C:\ProgramData\Anaconda3\Scripts\jupyter-notebook-script.py'
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
CommandLine | match | install |
CommandLine | match | pip.exe |
DestinationIp | eq | 127.0.0.1 |
SourceIp | eq | 127.0.0.1 |
CommandLine | match | :\ProgramData\Anaconda3\Scripts\conda-script.py |
CommandLine | match | update |
ParentImage | eq | C:\ProgramData\Anaconda3\Scripts\conda.exe |
CommandLine | match | C:\ProgramData\Anaconda3\Scripts\jupyter-notebook-script.py |
ParentImage | eq | C:\ProgramData\Anaconda3\python.exe |
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.