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Introduction
Prelude has unveiled a groundbreaking user-mode detection agent written in Rust, leveraging Intel Processor Trace (PT), Last Branch Record (LBR), and Performance Monitoring Unit (PMU) telemetry for advanced threat detection. This innovation enables high-fidelity monitoring without kernel-mode dependencies, enhancing security while minimizing system impact.
Learning Objectives
- Understand how Intel PT and PMU telemetry enhance threat detection.
- Learn how Prelude’s Rust-based agent operates in user-mode for efficiency and security.
- Explore real-world applications of hardware-backed telemetry in cybersecurity.
You Should Know
1. Intel Processor Trace (PT) for Threat Detection
Intel PT captures low-level execution traces, enabling forensic analysis of malicious activity. Below is a Linux command to enable PT tracing:
sudo perf record -e intel_pt//u -a -- sleep 10
Step-by-Step Guide:
1. Install `perf` if not present:
sudo apt install linux-tools-common linux-tools-generic
2. Run the PT trace for 10 seconds (sleep 10).
3. Analyze the output with:
sudo perf script --itrace=pt
This helps detect abnormal execution flows, such as code injection attacks.
- Monitoring Last Branch Records (LBR) in Windows
LBR tracks recent branch executions, useful for detecting ROP attacks. Enable LBR via PowerShell:
Get-WmiObject -Query "SELECT FROM Win32_PerfRawData_LBRMonitoring" | Format-List
Step-by-Step Guide:
1. Ensure LBR is enabled in BIOS.
- Use Windows Performance Analyzer (
wpr.exe) to capture LBR data.
3. Analyze logs for unexpected branch patterns.
3. Configuring PMU Telemetry in Rust
Prelude’s agent uses PMU counters for anomaly detection. A Rust snippet to read PMU events:
use perf_event::{Builder, Counter};
let mut counter = Builder::new().kind(perf_event::events::Hardware::CPU_CYCLES).build()?;
counter.enable()?;
let value = counter.read()?;
Step-by-Step Guide:
1. Add `perf-event` crate to `Cargo.toml`.
- Configure PMU events (e.g., cache misses, CPU cycles).
3. Compare baseline metrics to detect deviations.
4. User-Mode vs. Kernel-Mode Detection Tradeoffs
Kernel-mode agents (e.g., EDRs) have higher privileges but introduce stability risks. User-mode agents (like Prelude’s) are safer but may miss some events. Mitigate gaps with:
Linux: Use eBPF for user-kernel bridge
sudo bpftrace -e 'tracepoint:syscalls:sys_enter_execve { printf("%s\n", comm); }'
5. Rust for Secure Agent Development
Rust’s memory safety prevents common vulnerabilities. Example: Safe buffer handling in Rust vs. C:
// Rust (safe) let buffer: Vec<u8> = Vec::with_capacity(1024);
// C (unsafe) char buffer[bash]; // Potential overflow
6. API Security: Detecting Code Injection
Use Windows API `OpenProcess` with `PROCESS_QUERY_LIMITED_INFORMATION` to inspect processes without full access:
$proc = [System.Diagnostics.Process]::GetProcessById(1234)
$proc.Modules | Where-Object { $_.ModuleName -eq "malicious.dll" }
7. Cloud Hardening with Telemetry Integration
Forward PMU/PT logs to AWS CloudWatch:
aws logs put-log-events --log-group-name "PT-Traces" --log-stream-name "$(hostname)" --log-events file://events.json
What Undercode Say
- Key Takeaway 1: Hardware-backed telemetry (Intel PT, PMU) is revolutionizing detection by providing low-overhead, high-fidelity insights.
- Key Takeaway 2: Rust’s adoption in security agents reduces memory corruption risks while maintaining performance.
Analysis: Prelude’s approach bridges the gap between kernel and user-mode security, offering a scalable model for future EDR solutions. However, attackers may adapt by exploiting PT blind spots (e.g., hypervisor-level attacks).
Prediction
By 2026, 70% of EDRs will adopt hardware-assisted telemetry, forcing attackers to shift to firmware-level exploits. Organizations must integrate PMU/PT with behavioral AI to stay ahead.
References:
🎯Let’s Practice For Free:
IT/Security Reporter URL:
Reported By: Connor Mcgarr – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅


