Detection rules › Splunk

Windows IPC$ Share Access (Windows Event Log)

Group by
_time, host
Source
github.com/anvilogic-forge/armory

Winndows systems have hidden network shares that are accessible only to administrators and provide the ability for remote file copy and other administrative functions. This Use case identifies when network shares C$, ADMIN$, and IPC$ have had an object call. Adversaries may use this technique in conjunction with administrator-level Valid Accounts to remotely access a networked system

MITRE ATT&CK coverage

References

Telemetry coverage

Rule body

id: '5708.5980'
title: Windows IPC$ Share Access
description: 'Winndows systems have hidden network shares that are accessible only
  to administrators and provide the ability for remote file copy and other administrative
  functions. This Use case identifies when network shares C$, ADMIN$, and IPC$ have
  had an object call. Adversaries may use this technique in conjunction with administrator-level
  Valid Accounts to remotely access a networked system. -- Threat Actor Association:
  TA428, Volt Typhoon -- Atomics T1021.002 Test#1 Atomics T1021.002 Test#2 Atomics
  T1021.002 Test#4'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=5140) OR
  "<EventID>5140<" OR TERM(EventCode=5145) OR "<EventID>5145<") TERM(IPC) | regex
  Share_Name="(?i)ipc\$" | eval share_name=Share_Name, share_path=Share_Path, relative_target_name=Relative_Target_Name
  | table _time, host, user signature_id, share_*, src_ip, relative_target_name |
  bin span=1s | stats values(*) as * by _time, host '
techniques:
- lateral-movement:remote services:smb/windows admin shares
technique_id:
- T1021.002
data_category:
- Windows event logs
references:
- https://support.malwarebytes.com/hc/en-us/articles/360038524714

Stages and Predicates

Stage 1: search

`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=5140) OR "<EventID>5140<" OR TERM(EventCode=5145) OR "<EventID>5145<") TERM(IPC)

Stage 2: regex

| regex Share_Name="(?i)ipc\$"

Stage 3: eval

| eval share_name=Share_Name, share_path=Share_Path, relative_target_name=Relative_Target_Name

Stage 4: table

| table _time, host, user signature_id, share_*, src_ip, relative_target_name

Stage 5: bucket

| bin span=1s

Stage 6: stats

| stats values(*) as * by _time, host

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
EventCodeeq
  • 5140 corpus 8 (splunk 8)
  • 5145 corpus 23 (splunk 16, elastic 5, kusto 2)
field:"EventID" kind:eq
Share_Nameregex_match
  • "(?i)ipc$"
field:"Share_Name" kind:regex_match

Search terms

These SPL tokens match against raw event text.

StageTerm
1"<EventID>5140<"
1"<EventID>5145<"
1IPC