Certified: The Security+ Prepcast

In this episode, we are shifting focus to physical security threats and their indicators. While cybersecurity often centers on networks, data, and software, physical access to systems remains one of the most direct and potentially devastating vectors for attack. We’ll cover three common forms of physical compromise: brute force entry attempts, RFID cloning, and environmental sabotage. Each leaves behind indicators, and each requires a blend of monitoring and physical control to prevent and respond effectively.
Let’s begin with physical brute force attacks. In the digital world, brute force refers to systematically guessing passwords. But in physical security, brute force refers to forcibly gaining entry—often by damaging locks, prying open doors, or defeating access barriers with tools. These attacks may be opportunistic or targeted and are often used when attackers are trying to avoid digital detection.
Signs of a brute force attack include visible damage to locks, doors, badge readers, or control panels. You might see scuff marks, broken casing, or tampered hinges. Another common sign is a pattern of repeated failed access attempts on electronic locks or keypads. These may be logged in physical access control systems or noticed during routine inspections.
To mitigate brute force attacks, organizations should implement layered physical access controls. This includes badge readers, biometric access systems, and security vestibules or mantraps that only allow one person through at a time. Cameras should monitor all entry and exit points, and access logs should be reviewed for anomalies—especially outside of normal hours. Physical intrusion alarms, vibration sensors, and reinforced hardware also add strong deterrents against forced entry.
Now let’s turn to RFID cloning. Radio frequency identification, or RFID, is commonly used for access cards and badges. These devices transmit an ID signal to a reader, granting access to buildings, rooms, or secured zones. The problem is that standard RFID signals can be intercepted and copied using inexpensive tools, allowing attackers to clone an access badge and use it without authorization.
Cloned RFID cards can be difficult to detect unless systems are set up to monitor for anomalies. Indicators include access from a user ID at unexpected times, from multiple locations in rapid succession, or from areas the user has no legitimate reason to access. If the original badge is still in use and a cloned badge is active simultaneously, this creates a conflict in access logs that may point to malicious duplication.
To prevent RFID cloning, organizations should use secure, encrypted badge technologies—not basic low-frequency cards that are easily copied. Cards should include mutual authentication, and systems should be configured to lock out badges after multiple incorrect readings or unusual activity. Physical shielding, such as RFID-blocking badge holders, can prevent skimming attempts when cards are not in use.
Entry logs should be integrated with identity systems, and alerts should be triggered for irregular access patterns. Personnel should be trained to report lost or stolen cards immediately and understand the risks of tailgating—when someone follows a badge holder into a secure area without scanning their own credentials.
Lastly, let’s examine environmental attacks. These involve the manipulation or sabotage of systems that support critical infrastructure, such as heating, ventilation, air conditioning, or other environmental controls. An attacker might physically damage components, adjust settings to unsafe levels, or cut off power or network access to these systems.
Indicators of environmental attacks can include unexplained temperature changes in server rooms, loss of humidity control, sudden shutdowns of HVAC systems, or repeated sensor failures. If these conditions are not resolved quickly, they can lead to overheating, data loss, or hardware damage.
For example, a targeted environmental attack on a data center might involve disabling cooling systems to cause servers to overheat. While the attacker does not access the systems directly, the environmental disruption causes outages or permanent damage that serves their goals.
To defend against these attacks, organizations should install environmental monitoring sensors for temperature, humidity, airflow, and power. These sensors should trigger alerts when values fall outside defined ranges. Security personnel should regularly inspect physical infrastructure for signs of tampering. Access to HVAC and utility rooms should be restricted, monitored, and logged just like data centers.
Organizations should also incorporate environmental systems into their overall incident response plans. This includes having backups for environmental controls, redundancy in cooling or power, and trained personnel who can respond immediately to equipment alerts.
As you prepare for the Security Plus exam, understand that physical security is not just about locked doors. It includes monitoring for brute force attacks, detecting unauthorized badge use through RFID cloning, and identifying sabotage through environmental controls. The exam may present a scenario involving physical access or infrastructure failure, and your task will be to identify the signs of attack and recommend mitigation strategies. Think in terms of detection, access control, and environmental stability as the key layers of physical defense.