Files
splunk-security_content/detections/common_ransomware_extensions.yml
2020-05-06 17:42:38 +02:00

49 lines
2.2 KiB
YAML

name: Common Ransomware Extensions
id: a9e5c5db-db11-43ca-86a8-c852d1b2c0ec
version: 3
date: '2020-03-16'
description: The search looks for file modifications with extensions commonly used
by Ransomware
how_to_implement: 'You must be ingesting data that records the filesystem activity
from your hosts to populate the Endpoint file-system data model node. If you are
using Sysmon, you will need a Splunk Universal Forwarder on each endpoint from which
you want to collect data.\
This search produces fields (`query`,`query_length`,`count`) that are not yet supported
by ES Incident Review and therefore cannot be viewed when a notable event is raised.
These fields contribute additional context to the notable. To see the additional
metadata, add the following fields, if not already present, to Incident Review -
Event Attributes (Configure > Incident Management > Incident Review Settings > Add
New Entry):\\n1. **Label:** Name, **Field:** Name\
1. \
1. **Label:** File Extension, **Field:** file_extension\
Detailed documentation on how to create a new field within Incident Review may be
found here: `https://docs.splunk.com/Documentation/ES/5.3.0/Admin/Customizenotables#Add_a_field_to_the_notable_event_details`'
type: ESCU
references: []
author: David Dorsey, Splunk
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
as lastTime values(Filesystem.user) as user values(Filesystem.dest) as dest values(Filesystem.file_path)
as file_path from datamodel=Endpoint.Filesystem by Filesystem.file_name | `drop_dm_object_name(Filesystem)`
| `security_content_ctime(lastTime)` | `security_content_ctime(firstTime)`| rex
field=file_name "(?<file_extension>\.[^\.]+)$" | `ransomware_extensions` | `common_ransomware_extensions_filter`'
known_false_positives: It is possible for a legitimate file with these extensions
to be created. If this is a true ransomware attack, there will be a large number
of files created with these extensions.
tags:
analytics_story:
- SamSam Ransomware
- Ransomware
kill_chain_phases:
- Actions on Objectives
cis20:
- CIS 8
nist:
- PR.PT
- DE.CM
security_domain: endpoint
asset_type: Endpoint