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Description

This search is to detect potential plain HTTP POST method data exfiltration. This network traffic is commonly used by trickbot, trojanspy, keylogger or APT adversary where arguments or commands are sent in plain text to the remote C2 server using HTTP POST method as part of data exfiltration.

  • Type: TTP

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2021-04-22
  • Author: Teoderick Contreras, Splunk
  • ID: e2b36208-a364-11eb-8909-acde48001122

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1048.003 Exfiltration Over Unencrypted Non-C2 Protocol Exfiltration
T1048 Exfiltration Over Alternative Protocol Exfiltration
Kill Chain Phase
  • Actions On Objectives
NIST
  • DE.CM
CIS20
  • CIS 13
CVE 


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`stream_http` http_method=POST form_data IN ("*wermgr.exe*","*svchost.exe*", "*name=\"proclist\"*","*ipconfig*", "*name=\"sysinfo\"*", "*net view*") 
|stats values(form_data) as http_request_body min(_time) as firstTime max(_time) as lastTime count by http_method http_user_agent uri_path url bytes_in bytes_out 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `plain_http_post_exfiltrated_data_filter`

Macros

The SPL above uses the following Macros:

:information_source: plain_http_post_exfiltrated_data_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • http_method
  • http_user_agent
  • uri_path
  • url
  • bytes_in
  • bytes_out

How To Implement

To successfully implement this search, you need to be ingesting logs with the stream HTTP logs or network logs that catch network traffic. Make sure that the http-request-body, payload, or request field is enabled.

Known False Positives

unknown

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
63.0 70 90 A http post $http_method$ sending packet with plain text of information $form_data$ in uri path $uri_path$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

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