txt2detection

Overview

A command line tool that takes a txt file containing threat intelligence and turns it into a detection rule.

The problems

To illustrate the problem, lets walk through the current status quo process a human goes through when going from idea (threat TTP) to detection rule:

1. read and understand threat using their own research, aided by external sources (blogs, intel feed, etc.)

• problems: lots of reports, threats described in a range of ways, reports contain differing data

2. understand what logs or security data can be used to detect this threat

• problems: log schemas are unknown to analyst, TTPs often span many logs making it hard to ensure your detection rule has full coverage

3. convert the logic created in step 1 into a Sigma detection rule to search logs identified at step 2

• problems: hard to convert what has been understood into a logical detection rule (in a detection language an analyst might not be familiar with)

4. modify the detection rule based on new intelligence as it is discovered

• problems: this is typically overlooked as people create and forget about rules in their detection tools

The solution

Use AI to process threat intelligence, create and keep them updated.

txt2detection allows a user to enter some threat intelligence as a file to considered be turned into a detection.

1. User uploads intel report
2. Based on the user input, AI prompts structured and sent to produce an intelligence rule
3. Rules converted into STIX objects

Usage

Setup

Install the required dependencies using:

# clone the latest code
git clone https://github.com/muchdogesec/txt2detection
cd txt2detection
# create a venv
python3 -m venv txt2detection-venv
source txt2detection-venv/bin/activate
# install requirements
pip3 install -r requirements.txt
pip3 install .

Set variables

txt2detection has various settings that are defined in an .env file.

To create a template for the file:

cp .env.example .env

To see more information about how to set the variables, and what they do, read the .env.markdown file.

Then test your configoration

python3 txt2detection.py \
  check-credentials

It will return a response to show what API keys are working

============= Service Statuses ===============
  ctibutler   : authorized      ✔
  vulmatch    : authorized      ✔

  LLMS:
    openai      : authorized      ✔
    deepseek    : unsupported     –
    gemini      : unsupported     –
    openrouter  : unsupported     –
    anthropic   : unsupported     –

Not all services need to be configured, if you have no intention of using them.

Run

python3 txt2detection.py MODE \
  ARGUEMENTS

There are 3 modes in which you can use txt2detection:

• file: A text file, usually a threat report you want to create rules from the intel held within
• text: A text prompt that describes the rule you want to create
• sigma: An existing Sigma Rule you want to convert into a STIX bundle

File (file) / Text Input (text)

Use this mode to generate a set of rules from an input text file;

• --input_file (required, if not using --input_text, file path): the file to be converted. Must be .txt
• --input_text (required, if not using --input_file, string): a text string that will be analysed to create a rule by the AI if you don't want to use a file. Generally you want to be as descritive as possible with this text (consider it similar to an LLM propmpt). Very short input_texts will often cause the AI to fail at rule generation (you will see Unparsable output returned by LLM model).
• --name (required): name of file, max 72 chars. Will be used in the STIX Report Object created. Note, the Indicator object names/titles are generated by AI
• --report_id (optional, default random uuidv4): Sometimes it is required to control the id of the report object generated. You can therefore pass a valid UUIDv4 in this field to be assigned to the report. e.g. passing 2611965-930e-43db-8b95-30a1e119d7e2 would create a STIX object id report--2611965-930e-43db-8b95-30a1e119d7e2. If this argument is not passed, the UUID will be randomly generated.
• --tlp_level (optional, default clear): Options are clear, green, amber, amber_strict, red.
• --labels (optional): whitspace separated list of labels. Case-insensitive (will all be converted to lower-case). Allowed a-z, 0-9. Must use a namespaces (NAMESPACE.TAG_VALUE). e.g."namespace.label1" "namespace.label_2" would create 2 labels. Added to both report and indicator objects created and the rule tags.
  • note: you can use reserved namespaces cve. and attack. when creating labels to perform external enrichment using Vulmatch and CTI Butler. All Indicators will be linked to these objects (AI enrichments link individual rules). Created tags will be appended to the list of AI generated tags.
  • note: you cannot use the namespace tlp. Use the --tlp_level flag instead.
• --created (optional, YYYY-MM-DDTHH:MM:SS): by default all object created times will take the time the script was run. If you want to explicitly set these times you can do so using this flag. Pass the value in the format YYYY-MM-DDTHH:MM:SS e.g. 2020-01-01T00:00:00
• --use_identity (optional, default txt2detection identity): can pass a full STIX 2.1 identity object (make sure to properly escape). Will be validated by the STIX2 library. The ID is used to create the Indicator and Report STIX objects, and is used as the author property in the Sigma Rule.
• --license (optional): License of the rule according the SPDX ID specification. Will be added to the rule.
• --reference_urls (optional): A list of URLs to be added as references in the Sigma Rule property and in the external_references property of the Indicator and Report STIX object created. e.g "https://www.google.com/" "https://www.facebook.com/"
• --external_refs (optional): txt2detection will automatically populate the external_references of the report object it creates for the input. You can use this value to add additional objects to external_references. Note, you can only add source_name and external_id values currently. Pass as source_name=external_id. e.g. --external_refs txt2stix=demo1 source=id would create the following objects under the external_references property: {"source_name":"txt2stix","external_id":"demo1"},{"source_name":"source","external_id":"id"}
• --ai_provider (required): defines the provider:model to be used to generate the rule. Select one option. Currently supports:
  • Provider (env var required OPENROUTER_API_KEY): openrouter:, providers/models openai/gpt-4o, deepseek/deepseek-chat (More here)
  • Provider (env var required OPENAI_API_KEY): openai:, models e.g.: gpt-4o, gpt-4o-mini, gpt-4-turbo, gpt-4 (More here)
  • Provider (env var required ANTHROPIC_API_KEY): anthropic:, models e.g.: claude-3-5-sonnet-latest, claude-3-5-haiku-latest, claude-3-opus-latest (More here)
  • Provider (env var required GOOGLE_API_KEY): gemini:models/, models: gemini-1.5-pro-latest, gemini-1.5-flash-latest (More here)
  • Provider (env var required DEEPSEEK_API_KEY): deepseek:, models deepseek-chat (More here)
• --create_attack_navigator_layer (boolean, default false): passing this flag will generate a MITRE ATT&CK Navigator layer for MITRE ATT&CK tags. Note, Sigma currently supports ATT&CK Enterprise only.

Note, in this mode, the following values will be automatically assigned to the rule

• level: the AI will be prompted to assign, either informational, low, medium, high, critical
• status: will always be experimental in this mode

Sigma rule input (sigma)

Use this mode to turn a Sigma Rule into a STIX bundle and get it enriched with ATT&CK and Vulmatch.

Note, in this mode you should be aware of a few things;

• --sigma_file (required, file path): the sigma rule .yml you want to be processed. Must be a .yml or .yaml file. Does not currently support correlation rules.
• --report_id: will overwrite any id value found in the rule, also used for both Indicator and Report
• --name: will be assigned as title of the rule. Will overwrite existing title
• --tlp_level (optional): the tlp. tag in the report will be turned into a TLP level. If not TLP tag in rule, default is that is will be assigned TLP clear and tag added. You can pass clear, green, amber, amber_strict, red using this property to overwrite default behaviour. If TLP exist in rule, setting a value for this property will overwrite the existing value
• --labels (optional): whitespace separated list of labels. Case-insensitive (will all be converted to lower-case). Allowed a-z, 0-9. e.g."namespace.label1" "namespace.label2" would create 2 labels. Added to both report and indicator objects created and the rule tags. Note, if any existing tags in the rule, these values will be appended to the list.
  • note: you can use reserved namespaces cve. and attack. when creating labels to perform external enrichment using Vulmatch and CTI Butler. Created tags will be appended to the list of existing tags.
  • note: you cannot use the namespace tlp. Use the --tlp_level flag instead.
• --created (optional, YYYY-MM-DDTHH:MM:SS): by default the data and modified values in the rule will be used. If no values exist for these, the default behaviour is to use script run time. You can pass created time here which will overwrite date and modified date in the rule
• --use_identity (optional): can pass a full STIX 2.1 identity object (make sure to properly escape). Will be validated by the STIX2 library. The ID is used to create the Indicator and Report STIX objects, and is used as the author property in the Sigma Rule. Will overwrite any existing author value. If author value in rule, will be converted into a STIX Identity
• --license (optional): License of the rule according the SPDX ID specification. Will be added to the rule as license. Will overwrite any existing license value in rule.
• --reference_urls (optional): A list of URLs to be added as references in the Sigma Rule property and in the external_references property of the Indicator and Report STIX object created. e.g "https://www.google.com/" "https://www.facebook.com/". Will appended to any existing references in the rule.
• --external_refs (optional): txt2detection will automatically populate the external_references of the report object it creates for the input. You can use this value to add additional objects to external_references. Note, you can only add source_name and external_id values currently. Pass as source_name=external_id. e.g. --external_refs txt2stix=demo1 source=id would create the following objects under the external_references property: {"source_name":"txt2stix","external_id":"demo1"},{"source_name":"source","external_id":"id"}
• status (optional): either stable, test, experimental, deprecated, unsupported. If passed, will overwrite any existing status recorded in the rule
• level (optional): either informational, low, medium, high, critical. If passed, will overwrite any existing level recorded in the rule
• --create_attack_navigator_layer (boolean, default false): passing this flag will generate a MITRE ATT&CK Navigator layer for MITRE ATT&CK tags.

A note on observable extraction

txt2detection will automatically attempt to extract any observables (aka indicators of compromise) that are found in the created or imported rules to turn them into STIX objects joined to the STIX Indicator object of the Rule.

In txt2detection/observables.py you will find the observable types (and regexs used detection) currently supported.

Output

The output of each run is structured as follows;

.
├── logs
│   ├── log-<REPORT UUID>.log
│   ├── log-<REPORT UUID>.log
│   └── log-<REPORT UUID>.log
└── output
    └── bundle--<REPORT UUID>
        ├── rules
        │   ├── rule--<UUID>.yml
        │   └── rule--<UUID>.yml
        ├── data.json # AI output, useful for debugging
        └── bundle.json # final STIX bundle with all objects

Examples

See tests/manual-tests/README.md for some example commands.

Support

Minimal support provided via the DOGESEC community.

License

Apache 2.0.