mirror of
https://github.com/splunk/security_content
synced 2026-06-08 17:32:49 +00:00
Gowthamaraj rajendran
96 lines
4.0 KiB
YAML
96 lines
4.0 KiB
YAML
name: Linux Proxy Socks Curl
|
|
id: bd596c22-ad1e-44fc-b242-817253ce8b08
|
|
version: 1
|
|
date: '2022-07-29'
|
|
author: Michael Haag, Splunk
|
|
status: production
|
|
type: TTP
|
|
description: The following analytic identifies curl being utilized with a proxy based
|
|
on command-line arguments - -x, socks, --preproxy and --proxy. This behavior is
|
|
built into the MetaSploit Framework as a auxiliary module. What does socks buy an
|
|
adversary? SOCKS4a extends the SOCKS4 protocol to allow a client to specify a destination
|
|
domain name rather than an IP address. The SOCKS5 protocol is defined in RFC 1928.
|
|
It is an incompatible extension of the SOCKS4 protocol; it offers more choices for
|
|
authentication and adds support for IPv6 and UDP, the latter of which can be used
|
|
for DNS lookups. The protocols, and a proxy itself, allow an adversary to evade
|
|
controls in place monitoring traffic, making it harder for the defender to identify
|
|
and track activity.
|
|
data_source:
|
|
- Sysmon Event ID 1
|
|
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
|
|
as lastTime from datamodel=Endpoint.Processes where Processes.process_name=curl
|
|
Processes.process IN ("*-x *", "*socks4a://*", "*socks5h://*", "*socks4://*","*socks5://*",
|
|
"*--preproxy *", "--proxy*") by Processes.dest Processes.user Processes.parent_process_name
|
|
Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
|
|
| `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
|
|
| `linux_proxy_socks_curl_filter`'
|
|
how_to_implement: The detection is based on data that originates from Endpoint Detection
|
|
and Response (EDR) agents. These agents are designed to provide security-related
|
|
telemetry from the endpoints where the agent is installed. To implement this search,
|
|
you must ingest logs that contain the process GUID, process name, and parent process.
|
|
Additionally, you must ingest complete command-line executions. These logs must
|
|
be processed using the appropriate Splunk Technology Add-ons that are specific to
|
|
the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint`
|
|
data model. Use the Splunk Common Information Model (CIM) to normalize the field
|
|
names and speed up the data modeling process.
|
|
known_false_positives: False positives may be present based on proxy usage internally.
|
|
Filter as needed.
|
|
references:
|
|
- https://www.offensive-security.com/metasploit-unleashed/proxytunnels/
|
|
- https://curl.se/docs/manpage.html
|
|
- https://en.wikipedia.org/wiki/SOCKS
|
|
- https://oxylabs.io/blog/curl-with-proxy
|
|
- https://reqbin.com/req/c-ddxflki5/curl-proxy-server#:~:text=To%20use%20a%20proxy%20with,be%20URL%20decoded%20by%20Curl.
|
|
- https://gtfobins.github.io/gtfobins/curl/
|
|
tags:
|
|
analytic_story:
|
|
- Linux Living Off The Land
|
|
- Ingress Tool Transfer
|
|
asset_type: Endpoint
|
|
confidence: 80
|
|
impact: 70
|
|
message: An instance of $process_name$ was identified on endpoint $dest$ by user
|
|
$user$ utilizing a proxy. Review activity for further details.
|
|
mitre_attack_id:
|
|
- T1090
|
|
- T1095
|
|
observable:
|
|
- name: user
|
|
type: User
|
|
role:
|
|
- Victim
|
|
- name: dest
|
|
type: Hostname
|
|
role:
|
|
- Victim
|
|
- name: process_name
|
|
type: Process
|
|
role:
|
|
- Child Process
|
|
product:
|
|
- Splunk Enterprise
|
|
- Splunk Enterprise Security
|
|
- Splunk Cloud
|
|
required_fields:
|
|
- _time
|
|
- Processes.dest
|
|
- Processes.user
|
|
- Processes.parent_process_name
|
|
- Processes.parent_process
|
|
- Processes.original_file_name
|
|
- Processes.process_name
|
|
- Processes.process
|
|
- Processes.process_id
|
|
- Processes.parent_process_path
|
|
- Processes.process_path
|
|
- Processes.parent_process_id
|
|
risk_score: 56
|
|
security_domain: endpoint
|
|
tests:
|
|
- name: True Positive Test
|
|
attack_data:
|
|
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1105/atomic_red_team/curl-linux-sysmon.log
|
|
source: Syslog:Linux-Sysmon/Operational
|
|
sourcetype: sysmon_linux
|
|
update_timestamp: true
|