What Is Lateral Movement in Cybersecurity?

Imagine a burglar sneaks into a building—not to grab the first thing they find, but to quietly move from office to office, looking for valuable documents or keys to more secure rooms. That's lateral movement in the world of cybersecurity.

Lateral movement is a tactic used by cyber attackers after they gain initial access to a network. Instead of immediately stealing data or causing damage, they explore the network to find privileged accounts, critical systems, and sensitive data. It is a hallmark of stealthy and sophisticated attacks like ransomware campaigns and nation-state espionage.

Understanding lateral movement is critical for any business, especially small and mid-sized companies that may lack dedicated cybersecurity teams. If undetected, attackers can remain inside a network for weeks or even months, escalating privileges and increasing their control.

This article will walk you through what lateral movement means, how it works, the common methods attackers use, and how your organization can detect and stop them.

Lateral Movement Meaning & Definition

Lateral movement refers to the process by which an attacker, after initially breaching a single point in a network, moves across systems and accounts in search of valuable assets or elevated permissions. Unlike traditional attacks that are loud and disruptive, lateral movement is quiet and calculated. It often goes undetected because the attacker mimics legitimate user behavior. The goal is to reach high-value targets—such as domain controllers, finance servers, or intellectual property—without triggering alarms. This technique is a strategic part of larger attack campaigns used to maximize access and control.

What Types of Attacks Does Lateral Movement Enable?

Lateral movement itself is not an attack but a critical technique that facilitates a wide range of serious cyberattacks. By allowing attackers to move stealthily through a network, it sets the stage for several dangerous outcomes, including:

• Advanced Persistent Threats (APTs)
  These highly skilled attacker groups use lateral movement to maintain long-term, stealthy access to networks. They gather intelligence, exfiltrate sensitive data, and maintain persistence without being detected for months or even years.
• Ransomware Attacks
  Attackers use lateral movement to spread ransomware from the initially compromised system to other machines across the network. This maximizes the damage and leverage, as multiple critical systems get encrypted simultaneously.
• Data Breaches and Exfiltration
  Through lateral movement, attackers reach databases, file servers, or cloud resources containing confidential information. They can then steal or leak this data, causing financial and reputational harm.
• Privilege Escalation and System Control
  Lateral movement enables attackers to find accounts with administrative privileges. Gaining these allows them to control critical infrastructure, disable security tools, or create backdoors for future access.
• Insider Threats
  Malicious insiders or compromised employees may use lateral movement techniques to access systems beyond their normal permissions, increasing the risk and potential impact of internal breaches.

In summary, lateral movement is the enabler behind many sophisticated and damaging cyberattacks, making its detection and prevention a vital component of cybersecurity defense.

How Does Lateral Movement Work?

1. Initial Access

Every lateral movement begins with the attacker gaining a foothold in the network. This could happen through various means:

• Phishing emails that trick users into opening malicious attachments or clicking harmful links.
• Exploiting software vulnerabilities in exposed applications or operating systems.
• Compromised credentials, such as usernames and passwords obtained through data leaks or brute-force attacks.

Once inside, the attacker does not act immediately. Instead, they work to stay hidden and begin mapping the network.

2. Internal Exploration

After gaining initial access, the attacker starts collecting information about the internal environment. This step is critical, as it allows them to determine which systems to target next.

• They may scan for other connected devices, open ports, and running services.
• Tools like Netstat, Nmap, or built-in Windows commands may be used to map the network structure.
• The attacker checks which users are currently logged in and whether there are any cached credentials or saved sessions they can exploit.

The more they understand the environment, the more effectively they can plan their lateral movement.

3. Credential Theft and Privilege Escalation

To move across the network, the attacker typically needs higher-level credentials than the ones they initially stole. They achieve this through:

• Credential dumping: Extracting passwords or password hashes stored in memory or system files using tools like Mimikatz.
• Keylogging or token theft: Monitoring user activity to collect login information.
• Privilege escalation: Exploiting misconfigurations or vulnerabilities to grant themselves admin-level access.

At this point, the attacker can impersonate users or admins and begin accessing systems that would normally be off-limits.

4. Lateral Movement Proper

Armed with valid credentials and knowledge of the network layout, the attacker now begins true lateral movement:

• They remotely access other machines using legitimate protocols like RDP (Remote Desktop Protocol), SMB (Server Message Block), or WMI (Windows Management Instrumentation).
• They may use automation scripts or tools to copy malware or backdoors onto target machines.
• Because they use real credentials and built-in system tools, this activity often flies under the radar of basic security monitoring.

Lateral movement can continue for days or weeks as the attacker works toward their final objective.

Cyberattacks Examples Involving Lateral Movement

• Ryuk Ransomware: Ryuk ransomware attacks often begin with phishing emails or infected documents. Once inside the network, Ryuk operators use tools like Cobalt Strike and RDP to move laterally, identifying and encrypting high-value systems such as file servers and backup drives.
• SolarWinds Supply Chain Attack: In this high-profile breach, attackers compromised SolarWinds' Orion software and distributed malware through software updates. After gaining access to enterprise networks, they used lateral movement to target specific government and private-sector systems, maintaining persistence for months.

The 5 Stages of Lateral Movement

1. Reconnaissance
   The attacker surveys the network, identifying systems, users, and valuable targets. Tools and techniques may include port scanning, DNS queries, and traffic analysis.
2. Initial Access
   Entry is gained through phishing, exploit kits, or compromised remote access credentials.
3. Credential Access
   The attacker obtains more credentials through dumping, harvesting, or brute force.
4. Lateral Movement
   Using the collected credentials, the attacker moves between systems to expand access.
5. Objective Execution
   The attacker completes their mission, whether it's data theft, system control, or ransomware deployment. Often, they also establish persistence to return later.

This five-stage process can repeat in cycles if detection mechanisms are absent or weak.

How to Detect Lateral Movement

Detecting lateral movement is difficult because it often resembles legitimate activity. However, with the right tools and practices, you can spot it early.

Log and Traffic Monitoring

Monitor:

• Authentication logs (Windows Event ID 4624/4625 for logins)
• Remote access logs
• Network traffic between endpoints

Look for unusual login patterns, such as:

• Logins from new or unauthorized devices
• Access at strange hours
• High-frequency access to multiple systems

User and Entity Behavior Analytics (UEBA)

UEBA platforms use machine learning to detect deviations from typical user behavior. If an accountant's machine suddenly starts using PowerShell scripts or accessing IT servers, it may indicate compromise.

Endpoint Detection and Response (EDR)

EDR solutions monitor individual devices for signs of suspicious activity, like lateral tool usage or memory-based credential access. Solutions like Microsoft Defender for Endpoint, CrowdStrike Falcon, or SentinelOne offer strong EDR capabilities.

Security Information and Event Management (SIEM)

SIEM tools aggregate logs and alerts from across your infrastructure. They correlate events and can highlight potential lateral movement paths, especially when integrated with threat intelligence feeds.

How to Prevent Lateral Movement

Enforce the Principle of Least Privilege: Employees should only have access to the resources they need. Limit administrative privileges and review permissions regularly. Avoid shared or default admin credentials.

Implement Network Segmentation: Divide your network into isolated segments. For example, HR systems should be separate from production databases. Even if one area is compromised, segmentation limits how far the attacker can go.

Use Multi-Factor Authentication (MFA): MFA adds an extra layer of security. Even if attackers steal passwords, they are blocked without the second factor—whether it's a phone prompt, token, or biometric.

Patch Systems Promptly: Unpatched systems are prime targets. Apply security updates to operating systems, applications, and firmware regularly. Automated patch management systems can help maintain consistency.

Apply Zero Trust Architecture: Adopt a "never trust, always verify" mindset. Treat every user and device—inside or outside the network—as untrusted by default. Require continual authentication and authorization.

Conclusion: Why It Matters for Small Businesses

Lateral movement isn't just a concern for large corporations. In fact, small businesses are often more vulnerable. With fewer resources and weaker defenses, attackers find it easier to establish a foothold and move laterally with little resistance.

The consequences can be devastating—loss of sensitive data, ransomware lockdowns, or even regulatory penalties. But with proper understanding, vigilant monitoring, and layered defenses, you can drastically reduce your risk.

Start with what you can control: strengthen credentials, segment your network, and implement monitoring. Over time, invest in scalable tools like EDR or managed detection services. Preventing lateral movement may be your best line of defense against full-scale cyberattacks.