WARNING THIS IS A EXPERIMENTAL object

We have not been able to test, simulate, or build datasets for this object. Use at your own risk. This analytic is NOT supported.

Try in Splunk Security Cloud

Description

This search detects SIGRed via Zeek DNS and Zeek Conn data.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Network_Resolution
  • Last Updated: 2020-07-28
  • Author: Shannon Davis, Splunk
  • ID: c5c622e4-d073-11ea-87d0-0242ac130003

Annotations

ATT&CK
ID Technique Tactic
T1203 Exploitation for Client Execution Execution
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 8
  • CIS 16
CVE
ID Summary CVSS
CVE-2020-1350 A remote code execution vulnerability exists in Windows Domain Name System servers when they fail to properly handle requests, aka ‘Windows DNS Server Remote Code Execution Vulnerability’. 10.0
1
2
3
4
5
6
7
8
9
10
| tstats `security_content_summariesonly` count from datamodel=Network_Resolution where DNS.query_type IN (SIG,KEY) by DNS.flow_id 
| rename DNS.flow_id as flow_id 
| append [
| tstats  `security_content_summariesonly` count from datamodel=Network_Traffic where All_Traffic.bytes_in>65000 by All_Traffic.flow_id 
| rename All_Traffic.flow_id as flow_id] 
| `detect_windows_dns_sigred_via_zeek_filter` 
| stats count by flow_id 
| where count>1 
| fields - count 

Macros

The SPL above uses the following Macros:

Note that detect_windows_dns_sigred_via_zeek_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required field

  • _time
  • DNS.query_type
  • DNS.flow_id
  • All_Traffic.bytes_in
  • All_Traffic.flow_id

How To Implement

You must be ingesting Zeek DNS and Zeek Conn data into Splunk. Zeek data should also be getting ingested in JSON format. We are detecting SIG and KEY records via bro:dns:json and TCP payload over 65KB in size via bro:conn:json. The Network Resolution and Network Traffic datamodels are in use for this search.

Known False Positives

unknown

Associated Analytic story

RBA

Risk Score Impact Confidence Message
25.0 50 50 tbd

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

source | version: 1