add: Experimental expansion module to display the SIEM signatures from a sigma rule

Author: chrisr3d

README.md

@@ -38,6 +38,7 @@ For more information: [Extending MISP with Python modules](https://www.circl.lu/
 * [rbl](misp_modules/modules/expansion/rbl.py) - a module to get RBL (Real-Time Blackhost List) values from an attribute.
 * [reversedns](misp_modules/modules/expansion/reversedns.py) - Simple Reverse DNS expansion service to resolve reverse DNS from MISP attributes.
 * [shodan](misp_modules/modules/expansion/shodan.py) - a minimal [shodan](https://www.shodan.io/) expansion module.
+* [Sigma queries](misp_modules/modules/expansion/sigma_queries.py) - Experimental expansion module querying a sigma rule to convert it into all the available SIEM signatures.
 * [Sigma syntax validator](misp_modules/modules/expansion/sigma_syntax_validator.py) - Sigma syntax validator.
 * [sourcecache](misp_modules/modules/expansion/sourcecache.py) - a module to cache a specific link from a MISP instance.
 * [STIX2 pattern syntax validator](misp_modules/modules/expansion/stix2_pattern_syntax_validator.py) - a module to check a STIX2 pattern syntax.

misp_modules/modules/expansion/__init__.py

@@ -1,3 +1,3 @@
 from . import _vmray
 
-__all__ = ['vmray_submit', 'asn_history', 'circl_passivedns', 'circl_passivessl', 'countrycode', 'cve', 'dns', 'domaintools', 'eupi', 'farsight_passivedns', 'ipasn', 'passivetotal', 'sourcecache', 'virustotal', 'whois', 'shodan', 'reversedns', 'geoip_country', 'wiki', 'iprep', 'threatminer', 'otx', 'threatcrowd', 'vulndb', 'crowdstrike_falcon', 'yara_syntax_validator', 'hashdd', 'onyphe', 'onyphe_full', 'rbl', 'xforceexchange', 'sigma_syntax_validator', 'stix2_pattern_syntax_validator']
+__all__ = ['vmray_submit', 'asn_history', 'circl_passivedns', 'circl_passivessl', 'countrycode', 'cve', 'dns', 'domaintools', 'eupi', 'farsight_passivedns', 'ipasn', 'passivetotal', 'sourcecache', 'virustotal', 'whois', 'shodan', 'reversedns', 'geoip_country', 'wiki', 'iprep', 'threatminer', 'otx', 'threatcrowd', 'vulndb', 'crowdstrike_falcon', 'yara_syntax_validator', 'hashdd', 'onyphe', 'onyphe_full', 'rbl', 'xforceexchange', 'sigma_syntax_validator', 'stix2_pattern_syntax_validator', 'sigma_queries']

misp_modules/modules/expansion/sigma_queries.py

@@ -0,0 +1,50 @@
+import sys, os, io, json
+try:
+    from sigma.parser import SigmaCollectionParser
+    from sigma.config import SigmaConfiguration
+    from sigma.backends import getBackend, BackendOptions
+except ModuleNotFoundError:
+    print("sigma or yaml is missing, use 'pip3 install sigmatools' to install it.")
+
+misperrors = {'error': 'Error'}
+mispattributes = {'input': ['sigma'], 'output': ['text']}
+moduleinfo = {'version': '0.1', 'author': 'Christian Studer', 'module-type': ['expansion', 'hover'],
+              'description': 'An expansion hover module to display the result of sigma queries.'}
+moduleconfig = []
+sigma_targets = ('es-dsl', 'es-qs', 'graylog', 'kibana', 'xpack-watcher', 'logpoint', 'splunk', 'grep', 'wdatp', 'splunkxml', 'arcsight', 'qualys')
+
+def handler(q=False):
+    if q is False:
+        return False
+    request = json.loads(q)
+    if not request.get('sigma'):
+        misperrors['error'] = 'Sigma rule missing'
+        return misperrors
+    config = SigmaConfiguration()
+    backend_options = BackendOptions(None)
+    f = io.TextIOWrapper(io.BytesIO(request.get('sigma').encode()), encoding='utf-8')
+    parser = SigmaCollectionParser(f, config, None)
+    targets = []
+    old_stdout = sys.stdout
+    result = io.StringIO()
+    sys.stdout = result
+    for t in sigma_targets:
+        backend = getBackend(t)(config, backend_options, None)
+        try:
+            parser.generate(backend)
+            backend.finalize()
+            print("#NEXT")
+            targets.append(t)
+        except:
+            continue
+    sys.stdout = old_stdout
+    results = result.getvalue()[:-5].split('#NEXT')
+    d_result = {t: r.strip() for t,r in zip(targets, results)}
+    return {'results': [{'types': mispattributes['output'], 'values': d_result}]}
+
+def introspection():
+    return mispattributes
+
+def version():
+    moduleinfo['config'] = moduleconfig
+    return moduleinfo