Detection: Cisco NVM - Installation of Typosquatted Python Package

Updated Date: 2025-07-03 ID: 5e3f6b44-42cb-4f8a-99f0-59e78a52ea1d Author: Nasreddine Bencherchali, Splunk Type: TTP Product: Splunk Enterprise Security

Description

This analytic detects suspicious python package installations where the package name resembles popular Python libraries but may be typosquatted or slightly altered. Typosquatting is a common technique used by attackers to trick users into installing malicious packages that mimic legitimate ones. This detection leverages Cisco NVM flow telemetry and checks for pip or poetry package managers with the "install" or "add" flags, making outbound connections to package repository such as pypi.org with known or suspected typo package names.

Search

 1`cisco_network_visibility_module_flowdata`
 2dest_hostname IN ("*.pythonhosted.org", "*pypi.org", "*python-poetry.org")
 3(
 4  (process_arguments = "*pip*" process_arguments = "*install*")
 5  OR
 6  (process_arguments = "*poetry*" process_arguments = "*add*")
 7)
 8
 9| rex field=process_arguments "(?i)(?:pip
10|poetry)[^
11|]*?\s+(?:install
12|add)\s+(?P<package_name>[^\s\"']+)$"
13
14| lookup typo_squatted_python_packages
15         typosquatted_package_name as package_name
16         OUTPUTNEW comment package_official_url
17
18| where isnotnull(comment)
19
20| stats count min(_time) as firstTime max(_time) as lastTime
21        values(parent_process_arguments) as parent_process_arguments
22        values(process_arguments) as process_arguments
23        values(parent_process_hash) as parent_process_hash
24        values(process_hash) as process_hash
25        values(module_name_list) as module_name_list
26        values(module_hash_list) as module_hash_list
27        values(dest_port) as dest_port
28        values(aliul) as additional_logged_in_users_list
29        values(dest_hostname) as dest_hostname
30        by src dest parent_process_path parent_process_integrity_level process_path process_name process_integrity_level process_id transport package_name comment package_official_url
31
32| `security_content_ctime(firstTime)`
33
34| `security_content_ctime(lastTime)`
35
36| table firstTime lastTime src dest_hostname dest dest_port transport  package_name comment package_official_url
37  parent_process_integrity_level parent_process_path parent_process_arguments parent_process_hash
38  process_integrity_level process_path process_name process_arguments process_hash process_id
39  additional_logged_in_users_list module_name_list module_hash_list
40
41| `cisco_nvm___installation_of_typosquatted_python_package_filter`

Data Source

Name	Platform	Sourcetype	Source
Cisco Network Visibility Module Flow Data	Network	`'cisco:nvm:flowdata'`	`'not_applicable'`

Macros Used

Name	Value
cisco_network_visibility_module_flowdata	`sourcetype="cisco:nvm:flowdata"`
cisco_nvm___installation_of_typosquatted_python_package_filter	`search *`

cisco_nvm___installation_of_typosquatted_python_package_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1059	Command and Scripting Interpreter	Execution

Installation

DE.CM

CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Notable	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Risk Event	True

This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

This search requires Network Visibility Module logs, which includes the flow data sourcetype. This search uses an input macro named cisco_network_visibility_module_flowdata. We strongly recommend that you specify your environment-specific configurations (index, source, sourcetype, etc.) for Cisco Network Visibility Module logs. Replace the macro definition with configurations for your Splunk environment. The search also uses a post-filter macro designed to filter out known false positives. The logs are to be ingested using the Splunk Add-on for Cisco Endpoint Security Analytics (CESA) (https://splunkbase.splunk.com/app/4221). In addition to this, the search make use of the lookup "typo_squatted_python_packages". Which needs to be configured and tuned.

Known False Positives

False positives should be very minimal to non existent, as the names of the packages in the lookup are all extracted from previously malicious packages.

Associated Analytic Story

Cisco Network Visibility Module Analytics

Risk Based Analytics (RBA)

Risk Message:

Host $src$ used pip or poetry to install a likely typosquatted python package $package_name$ from $dest_hostname$

Risk Object	Risk Object Type	Risk Score	Threat Objects
src	system	60	process_name

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`not_applicable`	`cisco:nvm:flowdata`
Integration	✅ Passing	Dataset	`not_applicable`	`cisco:nvm:flowdata`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 1