# Identifying System Behavior In order to detect system behavior, we have 3 factors for this example. The first factor is intercepting the first 32 entries of IDT (Interrupt Descriptor Table). We use the [!exception](https://docs.hyperdbg.org/commands/extension-commands/exception) command for this purpose. For instance, if we want to break on **division-by-zero** on process id **0x490**. ```c HyperDbg> !exception 0x0 pid 490 ``` If we want to monitor external-interrupts (IDT index from **0x21** to **0xff**), we use the [!interrupt](https://docs.hyperdbg.org/commands/extension-commands/interrupt) command. Imagine we want to break on entry **0x25** of IDT. ```c HyperDbg> !interrupt 0x25 ``` The last factor is the system-wide monitoring of the execution of RDMSR and WRMSR. We use the [!msrread](https://docs.hyperdbg.org/commands/extension-commands/msrread) and the [!msrwrite](https://docs.hyperdbg.org/commands/extension-commands/msrwrite) commands. For example, MSR **0xc0000082 (LSTAR)** is one of the MSRs used by malware and rootkits. If we want to break on RDMSR to MSR **0xc0000082**. ```c HyperDbg> !msrread 0xc0000082 ``` If we want to break on WRMSR to MSR **0xc0000082**. ```c HyperDbg> !msrwrite 0xc0000082 ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.hyperdbg.org/using-hyperdbg/kernel-mode-debugging/examples/events/identifying-system-behavior.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.