mirror of
https://github.com/splunk/security_content
synced 2026-06-08 17:32:49 +00:00
Bhavin Patel
72 lines
2.1 KiB
YAML
72 lines
2.1 KiB
YAML
name: Linux Decode Base64 to Shell
|
|
id: 637b603e-1799-40fd-bf87-47ecbd551b66
|
|
version: 1
|
|
date: '2022-07-27'
|
|
author: Michael Haag, Splunk
|
|
status: production
|
|
type: TTP
|
|
description: The following analytic identifies base64 being decoded and passed to
|
|
a Linux shell.
|
|
data_source:
|
|
- Sysmon Event ID 1
|
|
search:
|
|
selection1:
|
|
CommandLine: '*|*'
|
|
selection2:
|
|
CommandLine:
|
|
- '*base64 -d*'
|
|
- '*base64 --decode*'
|
|
condition: selection1 and selection2
|
|
how_to_implement: To successfully implement this search you need to be ingesting information
|
|
on process that include the name of the process responsible for the changes from
|
|
your endpoints into the `Endpoint` datamodel in the `Processes` node. In addition,
|
|
confirm the latest CIM App 4.20 or higher is installed and the latest TA for the
|
|
endpoint product.
|
|
known_false_positives: False positives may be present based on legitimate software
|
|
being utilized. Filter as needed.
|
|
references:
|
|
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1027/T1027.md#atomic-test-1---decode-base64-data-into-script
|
|
- https://redcanary.com/blog/lateral-movement-with-secure-shell/
|
|
- https://linux.die.net/man/1/base64
|
|
tags:
|
|
analytic_story:
|
|
- Linux Living Off The Land
|
|
asset_type: Endpoint
|
|
confidence: 50
|
|
impact: 50
|
|
message: An instance of $parent_process_name$ spawning $process_name$ was identified
|
|
on endpoint $dest$ by user $user$ decoding base64 and passing it to a shell.
|
|
mitre_attack_id:
|
|
- T1027
|
|
- T1059.004
|
|
observable:
|
|
- name: user
|
|
type: User
|
|
role:
|
|
- Victim
|
|
- name: dest
|
|
type: Hostname
|
|
role:
|
|
- Victim
|
|
- name: parent_process_name
|
|
type: Process
|
|
role:
|
|
- Parent Process
|
|
- name: process_name
|
|
type: Process
|
|
role:
|
|
- Child Process
|
|
product:
|
|
- Splunk Enterprise
|
|
- Splunk Enterprise Security
|
|
- Splunk Cloud
|
|
risk_score: 25
|
|
security_domain: endpoint
|
|
tests:
|
|
- name: True Positive Test
|
|
attack_data:
|
|
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1027/atomic_red_team/linux-sysmon.log
|
|
source: Syslog:Linux-Sysmon/Operational
|
|
sourcetype: sysmon:linux
|
|
update_timestamp: true
|