What to inspect
- Source workstation.
- Destination hosts.
- TCP/445 activity.
- Account used.
- Authentication method.
- Number of destinations.
- Related process or administrative tool.
RR CYBERLAB • Threat Detection
Lateral Movement & SMB Investigation
Investigate internal host-to-host activity that may represent administration, file sharing or lateral movement.
QUICK READ
SMB is widely used for legitimate Windows operations, so lateral movement investigations require user, host, authentication and process context.
Use this page after the daily quiz: learn the concept first, then follow the investigation workflow and examples.
Investigation workflow
- Determine whether the source is an admin jump host.
- Identify whether the user is authorized to access the targets.
- Look for sequential access to many hosts.
- Correlate authentication and process events.
- Check whether the activity matches a maintenance window.
Example
A normal admin server accessing many servers may be expected. A user workstation suddenly accessing many hosts over SMB using an administrative account is more unusual and warrants investigation.Common mistakes
- Calling all SMB traffic lateral movement.
- Ignoring approved administration.
- Failing to scope all contacted hosts.
MITRE ATT&CK context
MITRE ATT&CK includes lateral movement techniques involving valid accounts and remote services; mapping should be based on observed behavior rather than the protocol alone. citeturn0search1
Map only behavior supported by the evidence; do not assign a technique merely because it is possible.
Daily quiz hook
Why is it important to know whether the source system is an approved administration host before classifying SMB activity as lateral movement?
Quiz flow: introduce this topic briefly on social media, ask the question, reveal the answer, then send learners here for the detailed investigation.
Analyst practice note
SMB is commonly used for file sharing and administration, so internal SMB traffic needs context. Investigate the initiating account, source and destination hosts, authentication result, share access, process lineage, and whether the connection matches an approved administrative path.
Follow the simulated host-to-host sequence and look for a change in account or system behavior. A single connection on port 445 is not proof of lateral movement; corroborate access and execution evidence and consider backup or management software.
Continue practicing: open a fictional mission and test your reasoning against the simulated evidence.