Aristotle
Aristotle is a simple Python program that allows for the filtering and modifying of Suricata and Snort rulesets based on interpreted key-value pairs present in the metadata keyword within each rule. It can be run as a standalone script or utilized as a module.
Documentation
https://aristotle-py.readthedocs.io/
Application Overview
Aristotle takes in a ruleset and can provide statistics on the included metadata keys. If a filter string is provided, it will also be applied against the ruleset and the filtered ruleset outputted.
Aristotle also offers the ability to intelligently process rules to extract, enrich, and add metadata to them. After initial filtering, rules can additionally undergo "Post Filter Modification" which can modify them based on user-defined criteria, to help ensure the resulting rules in the ruleset are enabled, configured, and optimized for the target environment.
Aristotle is compatible with Python 2.7 and Python 3.x.
| In order for Aristotle to be most useful, it should be provided a ruleset that has rules with the metadata keyword populated with appropriate key-value pairs. Aristotle assumes that the provided ruleset conforms to the BETTER Schema. |
Setup
Install dependencies:
pip install -r requirements.txt
Or if using as a module:
pip install aristotle
And refer to Aristotle as a Module.
Usage
usage: aristotle.py [-h] -r RULES [-f METADATA_FILTER]
[--summary [DISPLAY_MAX]] [-o OUTFILE]
[-s [STATS [STATS ...]]] [-i] [-c] [-n] [-e] [-t] [-g]
[-m] [-p PFMOD_FILE] [-q] [-d]
Filter Suricata and Snort rulesets based on metadata keyword values.
optional arguments:
-h, --help show this help message and exit
-r RULES, --rules RULES, --ruleset RULES
path to a rules file, a directory containing '.rules'
file(s), or string containing the ruleset
-f METADATA_FILTER, --filter METADATA_FILTER
Boolean filter string or path to a file containing it
--summary [DISPLAY_MAX]
output a summary of the filtered ruleset to stdout,
limited to DISPLAY_MAX number of lines (or 16 if no
value given); if the option to output to a file is
set, the full, filtered ruleset will still be written.
-o OUTFILE, --output OUTFILE
output file to write filtered ruleset to
-s [STATS [STATS ...]], --stats [STATS [STATS ...]]
display ruleset statistics about specified key(s). If
no key(s) supplied, then summary statistics for all
keys will be displayed.
-i, --enable-all-rules, --enable-all, --include-disabled
enable all valid rules, including those
disabled/commented out in the given rules file(s),
when applying the filter
-c, --output-disabled-rules
include disabled rules in the output as commented out
lines.
-n, --normalize, --better, --iso8601
try to convert date and cve related metadata values to
conform to the BETTER schema for filtering and
statistics. Dates are normalized to the format YYYY-
MM-DD and CVEs to YYYY-<num>. Also, 'sid' is removed
from the metadata.
-e, --enhance enhance metadata by adding additional key-value pairs
based on the rules.
-t, --ignore-classtype, --ignore-classtype-keyword
don't incorporate the 'classtype' keyword and value
from the rule into the metadata structure for
filtering and reporting.
-g, --ignore-filename
don't incorporate the 'filename' keyword (filename of
the rules file) into the metadata structure for
filtering and reporting.
-m, --modify-metadata
modify the rule metadata keyword value on output to
contain the internally tracked and normalized metadata
data.
-p PFMOD_FILE, --pfmod PFMOD_FILE, --pfmod-file PFMOD_FILE
YAML file of directives to apply actions on post-
filtered rules based on filter strings.
-q, --quiet, --suppress_warnings
quiet; suppress warning logging
-d, --debug turn on debug logging
A filter string defines the desired outcome based on Boolean logic, and uses
the metadata key-value pairs as values in a (concrete) Boolean algebra.
The key-value pair specifications must be surrounded by double quotes.
Example:
python3 aristotle/aristotle.py -r examples/example.rules --summary -n
-f '(("priority high" AND "malware <ALL>") AND "created_at >= 2018-01-01")
AND NOT ("protocols smtp" OR "protocols pop" OR "protocols imap") OR "sid 80181444"'License
Aristotle is licensed under the Apache License, Version 2.0.
Authors
- David Wharton
