A VM-based Intrusion Detection System (IDS) is a security mechanism designed to monitor and detect unauthorized or suspicious activities in a virtualized environment.
Intrusion Detection:
- Intrusion refers to unauthorized access to a system by local or remote users.
- Intrusion Detection System (IDS) is a software or hardware system that detects such intrusions.
- Two common types:
- Host-Based IDS (HIDS): Runs inside the operating system of the host. Risky because it can be compromised if the OS is attacked.
- Network-Based IDS (NIDS): Monitors network traffic. Safer but cannot detect fake actions or internal attacks effectively.
VM-Based IDS:
A VM-Based IDS uses virtualization technology to monitor and secure virtual machines (VMs) on the same physical server.
It combines the advantages of both HIDS and NIDS:
Two Methods of Implementation:
- High-Privileged VM Method:
- A special VM (called security VM) runs the IDS.
- It has high privileges over the VMM (Virtual Machine Monitor).
- Proposed by Garfinkel and Rosenblum.
- It monitors guest VMs from outside using tools like PTrace.
- VMM-Level Integration:
- The IDS is integrated directly into the VMM.
- It has the same privilege as the hypervisor.
- It can access hardware, memory, CPU, and all VM activities.
Components of a VM-Based IDS:
- Policy Engine:
- Contains the logic to detect abnormal behaviour.
- Uses rules or AI models to detect intrusions.
- Policy Module:
- Enforces the policies/rules across guest VMs.
- Operating System Interface Library:
- Allows the IDS to communicate with VMs safely.
Why Is It More Secure?
- Logs are stored and monitored outside the guest OS.
- Even if a guest OS is hacked, the IDS logs remain unaffected.
- This makes attack analysis and system recovery easier.
Honeypots:
- A honeypot is a decoy VM or system designed to lure attackers.
- Monitors attacker behavior to learn their techniques.
- Types:
- Physical honeypot: Uses real hardware.
- Virtual honeypot: Simulated using VMs.