mirror of https://github.com/MISP/misp-modules
55 lines
2.1 KiB
Python
55 lines
2.1 KiB
Python
import json
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import re
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try:
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import yara
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except (OSError, ImportError):
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print("yara is missing, use 'pip3 install -I -r REQUIREMENTS' from the root of this repository to install it.")
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misperrors = {'error': 'Error'}
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moduleinfo = {'version': '1', 'author': 'Christian STUDER',
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'description': 'Yara export for hashes.',
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'module-type': ['expansion', 'hover'],
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'require_standard_format': True}
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moduleconfig = []
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mispattributes = {'input': ['md5', 'sha1', 'sha256', 'filename|md5', 'filename|sha1', 'filename|sha256', 'imphash'], 'output': ['yara']}
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def get_hash_condition(hashtype, hashvalue):
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hashvalue = hashvalue.lower()
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required_module, params = ('pe', '()') if hashtype == 'imphash' else ('hash', '(0, filesize)')
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return '{}.{}{} == "{}"'.format(required_module, hashtype, params, hashvalue), required_module
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def handler(q=False):
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if q is False:
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return False
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request = json.loads(q)
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del request['module']
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if 'event_id' in request:
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del request['event_id']
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uuid = request.pop('attribute_uuid') if 'attribute_uuid' in request else None
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attribute_type, value = list(request.items())[0]
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if 'filename' in attribute_type:
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_, attribute_type = attribute_type.split('|')
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_, value = value.split('|')
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condition, required_module = get_hash_condition(attribute_type, value)
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import_section = 'import "{}"'.format(required_module)
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rule_start = '%s\r\nrule %s_%s {' % (import_section, attribute_type.upper(), re.sub(r'\W+', '_', uuid)) if uuid else '%s\r\nrule %s {' % (import_section, attribute_type.upper())
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condition = '\tcondition:\r\n\t\t{}'.format(condition)
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rule = '\r\n'.join([rule_start, condition, '}'])
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try:
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yara.compile(source=rule)
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except Exception as e:
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misperrors['error'] = 'Syntax error: {}'.format(e)
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return misperrors
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return {'results': [{'types': mispattributes['output'], 'values': rule}]}
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def introspection():
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return mispattributes
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def version():
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moduleinfo['config'] = moduleconfig
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return moduleinfo
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