Asi detecting-lateral-movement-with-splunk

Detect adversary lateral movement across networks using Splunk SPL queries against Windows authentication logs, SMB traffic, and remote service abuse.

install

source · Clone the upstream repo

git clone https://github.com/plurigrid/asi

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/plurigrid/asi "$T" && mkdir -p ~/.claude/skills && cp -r "$T/plugins/asi/skills/detecting-lateral-movement-with-splunk" ~/.claude/skills/plurigrid-asi-detecting-lateral-movement-with-splunk && rm -rf "$T"

manifest: plugins/asi/skills/detecting-lateral-movement-with-splunk/SKILL.md

Detecting Lateral Movement with Splunk

When to Use

When hunting for adversary movement between compromised systems
After detecting credential theft to trace subsequent lateral activity
When investigating unusual authentication patterns across the network
During incident response to scope the breadth of compromise
When proactively hunting for TA0008 (Lateral Movement) techniques

Prerequisites

Splunk Enterprise or Splunk Cloud with Windows event data ingested
Windows Security Event Logs forwarded (4624, 4625, 4648, 4672, 4768, 4769)
Sysmon deployed for process creation and network connection data
Network flow data or firewall logs for SMB/RDP/WinRM correlation
Active Directory user and group membership reference data

Workflow

Define Lateral Movement Scope: Identify which lateral movement techniques to hunt (RDP, SMB/Admin Shares, WinRM, PsExec, WMI, DCOM, SSH).
Query Authentication Events: Use SPL to search for Type 3 (Network) and Type 10 (RemoteInteractive) logons across the environment.
Build Authentication Graphs: Map source-to-destination authentication relationships to identify unusual connection patterns.
Detect First-Time Relationships: Identify new source-destination pairs that have not been seen in the historical baseline.
Correlate with Process Activity: Link authentication events to subsequent process creation on destination hosts.
Identify Anomalous Patterns: Flag lateral movement to sensitive servers, unusual hours, service account misuse, or rapid multi-host access.
Report and Contain: Document lateral movement path, affected systems, and coordinate containment response.

Key Concepts

Concept	Description
T1021	Remote Services (parent technique)
T1021.001	Remote Desktop Protocol (RDP)
T1021.002	SMB/Windows Admin Shares
T1021.003	Distributed COM (DCOM)
T1021.004	SSH
T1021.006	Windows Remote Management (WinRM)
T1570	Lateral Tool Transfer
T1047	Windows Management Instrumentation
T1569.002	Service Execution (PsExec)
Logon Type 3	Network logon (SMB, WinRM, mapped drives)
Logon Type 10	Remote Interactive (RDP)
Event ID 4624	Successful logon
Event ID 4648	Explicit credential logon (runas, PsExec)

Tools & Systems

Tool	Purpose
Splunk Enterprise	SIEM for log aggregation and SPL queries
Splunk Enterprise Security	Threat detection and notable events
Windows Event Forwarding	Centralize Windows logs
Sysmon	Detailed process and network telemetry
BloodHound	AD attack path analysis
PingCastle	AD security assessment

Common Scenarios

PsExec Lateral Movement: Adversary uses PsExec to execute commands on remote systems via SMB, generating Type 3 logon with ADMIN$ share access.
RDP Pivoting: Attacker RDPs to internal systems using stolen credentials, creating Type 10 logon events.
WMI Remote Execution: Adversary uses WMIC process call create to spawn processes on remote hosts.
WinRM PowerShell Remoting: Attacker uses Enter-PSSession or Invoke-Command to execute code on remote systems.
Pass-the-Hash via SMB: Compromised NTLM hashes used to authenticate to remote systems without knowing the plaintext password.

Output Format

Hunt ID: TH-LATMOV-[DATE]-[SEQ]
Movement Type: [RDP/SMB/WinRM/WMI/DCOM/PsExec]
Source Host: [Hostname/IP]
Destination Host: [Hostname/IP]
Account Used: [Username]
Logon Type: [3/10/other]
First Seen: [Timestamp]
Event Count: [Number of events]
Risk Level: [Critical/High/Medium/Low]
Lateral Movement Path: [A -> B -> C -> D]