Agent Skills: Detecting Lateral Movement with Splunk

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

1. Define Lateral Movement Scope: Identify which lateral movement techniques to hunt (RDP, SMB/Admin Shares, WinRM, PsExec, WMI, DCOM, SSH).
2. Query Authentication Events: Use SPL to search for Type 3 (Network) and Type 10 (RemoteInteractive) logons across the environment.
3. Build Authentication Graphs: Map source-to-destination authentication relationships to identify unusual connection patterns.
4. Detect First-Time Relationships: Identify new source-destination pairs that have not been seen in the historical baseline.
5. Correlate with Process Activity: Link authentication events to subsequent process creation on destination hosts.
6. Identify Anomalous Patterns: Flag lateral movement to sensitive servers, unusual hours, service account misuse, or rapid multi-host access.
7. 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

1. PsExec Lateral Movement: Adversary uses PsExec to execute commands on remote systems via SMB, generating Type 3 logon with ADMIN$ share access.
2. RDP Pivoting: Attacker RDPs to internal systems using stolen credentials, creating Type 10 logon events.
3. WMI Remote Execution: Adversary uses WMIC process call create to spawn processes on remote hosts.
4. WinRM PowerShell Remoting: Attacker uses Enter-PSSession or Invoke-Command to execute code on remote systems.
5. 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]