Are you prioritizing detections based on hypothetical risks or actual incidents? Alex Teixeira makes a compelling case for the “detection opportunity cost” – focusing resources on detection engineering for threats that have actually impacted your organization.
Key insights:
- Real incidents expose actual weaknesses in your defenses, not theoretical ones.
- Incidents provide free, golden threat data for developing and testing detections.
- Evidence-based prioritization ensures detection efforts align with your specific risk profile.
- Stakeholders more readily support initiatives tied to known impact events.
- Building detections on actual tactics used against you increases prevention efficacy.
Next incident response shouldn’t end with remediation—it should begin your detection engineering cycle!
You Should Know:
1. Extracting Threat Data from Logs
Use Linux commands to analyze logs for detection engineering:
Check failed login attempts
grep "Failed password" /var/log/auth.log
Extract suspicious IPs
awk '/Failed password/{print $11}' /var/log/auth.log | sort | uniq -c | sort -nr
Monitor process execution
ps aux | grep -E "(sh|bash|python|perl|wget|curl)"
2. Windows Event Log Analysis
Use PowerShell to extract security events:
Get failed login attempts
Get-WinEvent -FilterHashtable @{LogName='Security'; ID=4625}
Extract process creation logs
Get-WinEvent -FilterHashtable @{LogName='Security'; ID=4688} | Select-Object -First 10
3. Automating Detection with Sigma Rules
Use Sigma, an open-source detection rule format:
title: Suspicious Process Execution description: Detects unusual process execution patterns logsource: product: windows service: security detection: selection: EventID: 4688 CommandLine: - 'powershell -nop -exec bypass' - 'certutil -urlcache' condition: selection
4. Testing Detections with Atomic Red Team
Simulate attacks to validate detections:
Install Atomic Red Team sh -c "$(curl -sSL https://raw.githubusercontent.com/redcanaryco/atomic-red-team/master/atomic-red-team/inventory/install.sh)" Run a test (e.g., credential dumping) atomic-red-team execute --technique T1003
5. SIEM Querying (Splunk Example)
index=wineventlog EventCode=4688 | stats count by CommandLine | search CommandLine="powershell -nop"
What Undercode Say:
Detection engineering must be rooted in real-world incidents rather than theoretical threats. By leveraging actual attack data, security teams can:
– Reduce false positives by focusing on observed adversary behavior.
– Improve response times with context-aware detections.
– Optimize resource allocation by prioritizing high-impact threats.
Key Commands to Enhance Detection:
Network traffic analysis tcpdump -i eth0 'port 80 or port 443' -w traffic.pcap Check for hidden processes ls -la /proc//exe 2>/dev/null | grep deleted Analyze scheduled tasks crontab -l
Windows Forensic Commands:
Check for persistence Get-ItemProperty -Path "HKLM:\Software\Microsoft\Windows\CurrentVersion\Run" Extract PowerShell history type $env:USERPROFILE\AppData\Roaming\Microsoft\Windows\PowerShell\PSReadLine\ConsoleHost_history.txt
Expected Output:
A data-driven detection strategy that evolves with real incidents, supported by automated threat analysis and SIEM integration.
Prediction:
Organizations that adopt evidence-based detection engineering will see a 30% reduction in breach impact within the next two years.
References:
Reported By: Patrick Bareiss – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
