Possible Ransomware or unauthorized MBR modifications

Detects, possibly, malicious unauthorized usage of bcdedit.exe

Rule Content

- title: Possible Ransomware or unauthorized MBR modifications
  id: c9fbe8e9-119d-40a6-9b59-dd58a5d84429
  status: experimental
  description: Detects, possibly, malicious unauthorized usage of bcdedit.exe
  references:
  - https://docs.microsoft.com/en-us/windows-hardware/drivers/devtest/bcdedit--set
  author: '@neu5ron'
  date: 2019/02/07
  tags:
  - attack.defense_evasion
  - attack.t1070
  - attack.persistence
  - attack.t1067
  logsource:
    category: process_creation
    product: windows
    service: null
  detection:
    selection:
      NewProcessName: '*\bcdedit.exe'
      ProcessCommandLine:
      - '*delete*'
      - '*deletevalue*'
      - '*import*'
    condition: selection
  level: medium

Querying Elasticsearch

Import Libraries



In [ ]:

    
from elasticsearch import Elasticsearch
from elasticsearch_dsl import Search
import pandas as pd

Initialize Elasticsearch client



In [ ]:

    
es = Elasticsearch(['http://helk-elasticsearch:9200'])
searchContext = Search(using=es, index='logs-*', doc_type='doc')

Run Elasticsearch Query



In [ ]:

    
s = searchContext.query('query_string', query='(process_path.keyword:*\\bcdedit.exe AND process_command_line.keyword:(*delete* OR *deletevalue* OR *import*))')
response = s.execute()
if response.success():
    df = pd.DataFrame((d.to_dict() for d in s.scan()))

Show Results



In [ ]:

    
df.head()