Skip to content

Latest commit

 

History

History
319 lines (234 loc) · 14.1 KB

CLI.md

File metadata and controls

319 lines (234 loc) · 14.1 KB
Raw

Command Line Interface (CLI)

This covers more advanced CLI use cases and workflows. To get started with the CLI, reference the README. Basic use of the CLI such as creating a rule or testing are referenced in the contribution guide.

Using a config file or environment variables

CLI commands which are tied to Kibana and Elasticsearch are capable of parsing auth-related keyword args from a config file or environment variables.

If a value is set in multiple places, such as config file and environment variable, the order of precedence will be as follows:

  • explicitly passed args (such as --user joe)
  • environment variables
  • config values
  • prompt (this only applies to certain values)

Setup a config file

In the root directory of this repo, create the file .detection-rules-cfg.json and add relevant values

Currently supported arguments:

  • elasticsearch_url
  • kibana_url
  • cloud_id
  • *_username (kibana and es)
  • *_password (kibana and es)

Using environment variables

Environment variables using the argument format: DR_<UPPERCASED_ARG_NAME> will be parsed in commands which expect it. EX: DR_USER=joe

Using the environment variable DR_BYPASS_NOTE_VALIDATION_AND_PARSE will bypass the Detection Rules validation on the note field in toml files.

Importing rules into the repo

You can import rules into the repo using the create-rule or import-rules commands. Both of these commands will require that the rules are schema-compliant and able to pass full validation. The biggest benefit to using these commands is that they will strip* additional fields** and prompt for missing required fields.

Alternatively, you can manually place rule files in the directory and run tests to validate as well.

* Note: This is currently limited to flat fields and may not apply to nested values.
** Note: Additional fields are based on the current schema at the time the command is used.

create-rule

Usage: detection_rules create-rule [OPTIONS] PATH

  Create a detection rule.

Options:
  -c, --config FILE               Rule or config file
  --required-only                 Only prompt for required fields
  -t, --rule-type [machine_learning|saved_query|query|threshold]
                                  Type of rule to create
  -h, --help                      Show this message and exit.

This command will allow you to pass a rule file using the -c/--config parameter. This is limited to one rule at a time and will accept any valid rule in the following formats:

  • toml
  • json
  • yaml (yup)
  • ndjson (as long as it contains only a single rule and has the extension .ndjson or .jsonl)

import-rules

Usage: detection_rules import-rules [OPTIONS] [INPUT_FILE]...

  Import rules from json, toml, or Kibana exported rule file(s).

Options:
  -d, --directory DIRECTORY  Load files from a directory
  -h, --help                 Show this message and exit.

The primary advantage of using this command is the ability to import multiple rules at once. Multiple rule paths can be specified explicitly with unlimited arguments, recursively within a directory using -d/--directory*, or a combination of both.

In addition to the formats mentioned using create-rule, this will also accept an .ndjson/jsonl file containing multiple rules (as would be the case with a bulk export).

This will also strip additional fields and prompt for missing required fields.

* Note: This will attempt to parse ALL files recursively within a specified directory.

Commands using Elasticsearch and Kibana clients

Commands which connect to Elasticsearch or Kibana are embedded under the subcommands:

  • es
  • kibana

These command groups will leverage their respective clients and will automatically use parsed config options if defined, otherwise arguments should be passed to the sub-command as:

python -m detection-rules kibana -u <username> -p <password> upload-rule <...>

python -m detection_rules es -h

Usage: detection_rules es [OPTIONS] COMMAND [ARGS]...

  Commands for integrating with Elasticsearch.

Options:
  -et, --timeout INTEGER        Timeout for elasticsearch client
  -ep, --es-password TEXT
  -eu, --es-user TEXT
  --cloud-id TEXT
  -e, --elasticsearch-url TEXT
  -h, --help                    Show this message and exit.

Commands:
  collect-events  Collect events from Elasticsearch.

Providers are the name that Elastic Cloud uses to configure authentication in Kibana. When we create deployment, Elastic Cloud configures two providers by default: basic/cloud-basic and saml/cloud-saml (for SSO).

python -m detection_rules kibana -h

█▀▀▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄   ▄      █▀▀▄ ▄  ▄ ▄   ▄▄▄ ▄▄▄
█  █ █▄▄  █  █▄▄ █    █   █  █ █ █▀▄ █      █▄▄▀ █  █ █   █▄▄ █▄▄
█▄▄▀ █▄▄  █  █▄▄ █▄▄  █  ▄█▄ █▄█ █ ▀▄█      █ ▀▄ █▄▄█ █▄▄ █▄▄ ▄▄█

Usage: detection_rules kibana [OPTIONS] COMMAND [ARGS]...

  Commands for integrating with Kibana.

Options:
  --ignore-ssl-errors TEXT
  --space TEXT                 Kibana space
  --provider-name TEXT         For cloud deployments, Elastic Cloud configures
                               two providers by default: cloud-basic and
                               cloud-saml (for SSO)
  --provider-type TEXT         For cloud deployments, Elastic Cloud configures
                               two providers by default: basic and saml (for
                               SSO)
  -ku, --kibana-user TEXT
  --kibana-url TEXT
  -kp, --kibana-password TEXT
  -kc, --kibana-cookie TEXT    Cookie from an authed session
  --cloud-id TEXT              ID of the cloud instance. Defaults the cloud
                               provider to cloud-basic if this option is
                               supplied
  -h, --help                   Show this message and exit.

Commands:
  search-alerts  Search detection engine alerts with KQL.
  upload-rule    Upload a list of rule .toml files to Kibana.

Searching Kibana for Alerts

Alerts stored in Kibana can be quickly be identified by searching with the search-alerts command.

python -m detection_rules kibana search-alerts -h

Kibana client:
Options:
  --ignore-ssl-errors TEXT
  --space TEXT                 Kibana space
  --provider-name TEXT         For cloud deployments, Elastic Cloud configures
                               two providers by default: cloud-basic and
                               cloud-saml (for SSO)
  --provider-type TEXT         For cloud deployments, Elastic Cloud configures
                               two providers by default: basic and saml (for
                               SSO)
  -ku, --kibana-user TEXT
  --kibana-url TEXT
  -kp, --kibana-password TEXT
  -kc, --kibana-cookie TEXT    Cookie from an authed session
  --cloud-id TEXT              ID of the cloud instance. Defaults the cloud
                               provider to cloud-basic if this option is
                               supplied

Usage: detection_rules kibana search-alerts [OPTIONS] [QUERY]

  Search detection engine alerts with KQL.

Options:
  -d, --date-range <TEXT TEXT>...
                                  Date range to scope search
  -c, --columns TEXT              Columns to display in table
  -e, --extend                    If columns are specified, extend the
                                  original columns
  -h, --help                      Show this message and exit.

Running the following command will print out a table showing any alerts that have been generated recently. python3 -m detection_rules kibana --provider-name cloud-basic --kibana-url <url> --kibana-user <username> --kibana-password <password> search-alerts

█▀▀▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄   ▄      █▀▀▄ ▄  ▄ ▄   ▄▄▄ ▄▄▄
█  █ █▄▄  █  █▄▄ █    █   █  █ █ █▀▄ █      █▄▄▀ █  █ █   █▄▄ █▄▄
█▄▄▀ █▄▄  █  █▄▄ █▄▄  █  ▄█▄ █▄█ █ ▀▄█      █ ▀▄ █▄▄█ █▄▄ █▄▄ ▄▄█

===================================================================================================================================
 host                                 rule
 hostname                             name                                                                @timestamp
===================================================================================================================================
 stryker-malwares-MacBook-Pro.local   Sudo Heap-Based Buffer Overflow Attempt                             2022-06-21T14:08:34.288Z
 stryker-malwares-MacBook-Pro.local   Suspicious Automator Workflows Execution                            2022-06-21T13:58:30.857Z
 stryker-malwares-MacBook-Pro.local   Privilege Escalation Enumeration via LinPEAS                        2022-06-21T13:33:18.218Z
 stryker-malwares-MacBook-Pro.local   Privilege Escalation Enumeration via LinPEAS                        2022-06-21T13:28:14.685Z
 stryker-malwares-MacBook-Pro.local   Potential Reverse Shell Activity via Terminal                       2022-06-21T12:53:00.234Z
 stryker-malwares-MacBook-Pro.local   Potential Reverse Shell Activity via Terminal                       2022-06-21T12:53:00.237Z
 stryker-malwares-MacBook-Pro.local   Potential Kerberos Attack via Bifrost                               2022-06-20T20:33:53.810Z
 stryker-malwares-MacBook-Pro.local   Potential Kerberos Attack via Bifrost                               2022-06-20T20:33:53.813Z
 stryker-malwares-MacBook-Pro.local   Potential Privilege Escalation via Root Crontab File Modification   2022-06-20T20:23:50.557Z
 stryker-malwares-MacBook-Pro.local   Download and Execution of JavaScript Payload                        2022-06-20T20:18:46.211Z
===================================================================================================================================

Uploading rules to Kibana

Toml formatted rule files can be uploaded as custom rules using the kibana upload-rule command. To upload more than one file, specify multiple files at a time as individual args. This command is meant to support uploading and testing of rules and is not intended for production use in its current state.

python -m detection_rules kibana upload-rule -h

Kibana client:
Options:
  --space TEXT                 Kibana space
  -kp, --kibana-password TEXT
  -ku, --kibana-user TEXT
  --cloud-id TEXT
  -k, --kibana-url TEXT

Usage: detection_rules kibana upload-rule [OPTIONS]

  Upload a list of rule .toml files to Kibana.

Options:
  -f, --rule-file FILE
  -d, --directory DIRECTORY  Recursively export rules from a directory
  -id, --rule-id TEXT
  -r, --replace-id           Replace rule IDs with new IDs before export
  -h, --help                 Show this message and exit.
(detection-rules-build) (base) ➜  detection-rules git:(rule-loader) ✗

Alternatively, rules can be exported into a consolidated ndjson file which can be imported in the Kibana security app directly.

Usage: detection_rules export-rules [OPTIONS]

  Export rule(s) into an importable ndjson file.

Options:
  -f, --rule-file FILE
  -d, --directory DIRECTORY       Recursively export rules from a directory
  -id, --rule-id TEXT
  -o, --outfile FILE              Name of file for exported rules
  -r, --replace-id                Replace rule IDs with new IDs before export
  --stack-version [7.8|7.9|7.10|7.11|7.12]
                                  Downgrade a rule version to be compatible
                                  with older instances of Kibana
  -s, --skip-unsupported          If `--stack-version` is passed, skip rule
                                  types which are unsupported (an error will
                                  be raised otherwise)
  -h, --help                      Show this message and exit.

*To load a custom rule, the proper index must be setup first. The simplest way to do this is to click the Load prebuilt detection rules and timeline templates button on the detections page in the Kibana security app.

Converting between JSON and TOML

Importing rules will convert from any supported format to toml. Additionally, the command view-rule will also allow you to view a converted rule without importing it by specifying the --rule-format flag.

To view a rule in JSON format, you can also use the view-rule command with the --api-format flag, which is the default. (See the note on the JSON formatted rules and versioning)

A note on version handling

The rule toml files exist slightly different than they do in their final state as a JSON file in Kibana. The files are white space stripped, normalized, sorted, and indented, prior to their json conversion. Everything within the metadata table is also stripped out, as this is meant to be used only in the context of this repository and not in Kibana..

Additionally, the version of the rule is added to the file prior to exporting it. This is done to restrict version bumps to occur intentionally right before we create a release. Versions are auto-incremented based on detected changes in rules. This is based on the hash of the rule in the following format:

  • sorted json
  • serialized
  • b64 encoded
  • sha256 hash

As a result, all cases where rules are shown or converted to JSON are not just simple conversions from TOML.

Debugging

Most of the CLI errors will print a concise, user friendly error. To enable debug mode and see full error stacktraces, you can define "debug": true in your config file, or run python -m detection-rules -d <commands...>.

Precedence goes to the flag over the config file, so if debug is enabled in your config and you run python -m detection-rules --no-debug, debugging will be disabled.