What is lateral movement? How attackers spread through your network

What is lateral movement?

Lateral movement is what happens after the initial breach. An attacker has gained access to one system, but their target is somewhere else: a database with customer data, an admin console, a cloud account with elevated privileges. Lateral movement is the process of navigating from that initial foothold to the systems that matter.

The MITRE ATT&CK framework catalogs lateral movement as a distinct tactic, documenting techniques attackers commonly use:

Pass-the-hash and pass-the-ticket. Reusing stolen authentication credentials to access other systems without knowing the actual password.
Remote service exploitation. Using protocols like RDP, SSH, or SMB to connect to other systems using compromised credentials.
Internal spear phishing. Sending phishing messages from a compromised internal account to gain access to additional users' systems.
Exploitation of internal services. Targeting vulnerabilities in internal applications or services that aren't exposed to the internet but are accessible from the compromised system.

Lateral movement is why a single compromised endpoint can lead to a full-scale breach. The attacker's initial access point is rarely the final target. It's the starting position for a broader campaign.

Why lateral movement matters for startups

According to IBM's 2025 Cost of a Data Breach report, the average time to detect a breach is 204 days. During that time, attackers are moving laterally through the environment, escalating privileges, and accessing increasingly sensitive systems. The longer lateral movement goes undetected, the more damage is done.

Here's why startups should care:

Flat networks enable unrestricted movement. Many startups operate with minimal network segmentation. Every service can talk to every other service. This means an attacker who compromises a single development laptop can potentially reach production databases, CI/CD pipelines, and cloud admin consoles without hitting any barriers.
Overprivileged accounts accelerate lateral movement. When service accounts have broad permissions, developers have admin access they don't need, and API keys grant access to everything, lateral movement becomes trivial. The attacker doesn't need sophisticated techniques when a single compromised credential unlocks the entire environment.
Zero trust is the architectural counter. Zero trust principles, especially least-privilege access, network segmentation, and continuous verification, are specifically designed to limit lateral movement. Even if an attacker breaches one system, zero trust architecture prevents them from freely accessing others.
Detection requires visibility. Identifying lateral movement requires monitoring internal traffic patterns, authentication events, and privilege usage. Without a SIEM or equivalent monitoring, lateral movement happens silently.

How Fencer helps limit lateral movement

Fencer addresses lateral movement at the prevention layer. By identifying misconfigurations (overprivileged IAM roles, open internal ports, missing network segmentation), code-level vulnerabilities that could serve as pivot points, and exposed credentials, Fencer helps eliminate the paths attackers would use to move laterally. Fixing these issues before a breach means an attacker who gains initial access has nowhere to go.

Frequently asked questions

How do attackers perform lateral movement in cloud environments?

In cloud environments, lateral movement often exploits IAM misconfigurations rather than traditional network protocols. Attackers might compromise an overprivileged service account and use its permissions to access other cloud resources (S3 buckets, databases, other compute instances). They may exploit instance metadata services to steal temporary credentials, use compromised API keys to enumerate and access additional services, or pivot through connected SaaS applications. Cloud-native lateral movement is often harder to detect because it uses legitimate APIs and authenticated sessions rather than suspicious network traffic.

What's the difference between lateral movement and privilege escalation?

Privilege escalation is about gaining higher permissions on a system or within an environment (going from a regular user to an admin). Lateral movement is about accessing additional systems or resources across the network. In practice, attackers often combine both: they gain initial access with low privileges, escalate privileges on the compromised system, then use those elevated privileges to move laterally to other systems. Both are stages in a typical attack chain, with privilege escalation often enabling more effective lateral movement.

How can a startup detect lateral movement?

Start with authentication monitoring: unusual login patterns, service accounts accessing resources they've never touched, users authenticating from unexpected locations, or multiple failed authentication attempts across different systems. Network-level monitoring can detect unusual internal traffic patterns (a web server suddenly communicating with a database it's never connected to). Cloud audit logs (AWS CloudTrail, GCP Audit Logs) can reveal unexpected API calls or cross-service access. A SIEM helps correlate these signals across your environment. Even without a SIEM, enabling and reviewing cloud audit logs and authentication logs is a baseline detection capability.

Lateral Movement