Suspicious PowerShell Download

Detects suspicious PowerShell download command

Rule Content

- title: Suspicious PowerShell Download
  id: 65531a81-a694-4e31-ae04-f8ba5bc33759
  status: experimental
  description: Detects suspicious PowerShell download command
  tags:
  - attack.execution
  - attack.t1086
  author: Florian Roth
  logsource:
    product: windows
    service: powershell
    category: null
  detection:
    keywords:
      Message:
      - '*System.Net.WebClient).DownloadString(*'
      - '*system.net.webclient).downloadfile(*'
    condition: keywords
  falsepositives:
  - PowerShell scripts that download content from the Internet
  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-endpoint-winevent-powershell-*', doc_type='doc')

Run Elasticsearch Query



In [ ]:

    
s = searchContext.query('query_string', query='Message.keyword:(*System.Net.WebClient\).DownloadString\(* OR *system.net.webclient\).downloadfile\(*)')
response = s.execute()
if response.success():
    df = pd.DataFrame((d.to_dict() for d in s.scan()))

Show Results



In [ ]:

    
df.head()