Detection & Analysis Stage (Part 1)

---

1. Detection & Analysis Overview

Purpose: To detect security incidents effectively and conduct an initial investigation to establish context before escalating the response.

• Why: Proper detection and analysis ensure that incidents are identified early, reducing the time to respond and minimizing potential damage. Contextual understanding prevents misinterpretation of events and ensures appropriate actions are taken.

---

2. Levels of Detection

Purpose: To implement a layered detection strategy by logically categorizing the network into different levels.

• Why: A multi-layered detection approach ensures comprehensive visibility across the network, making it harder for threats to go unnoticed.

• Technical Example:

  • Detection at the Network Perimeter:

    • Use firewalls, IDS/IPS, and DMZ configurations to monitor traffic entering and leaving the network:

      • Example firewall rule to log suspicious outbound traffic:

        iptables -A OUTPUT -p tcp --dport 4444 -j LOG --log-prefix "Suspicious Outbound Traffic: "

      • Configure IDS/IPS systems like Snort or Suricata to detect malicious activity:

        alert tcp any any -> any any (msg:"Malicious Payload Detected"; content:"evil_payload"; sid:1000001;)

  • Detection at the Internal Network Level:

    • Deploy host-based firewalls and HIDS/HIPS to monitor internal traffic:

      • Example Windows Defender Firewall rule to block workstation-to-workstation communication:

        New-NetFirewallRule -DisplayName "Block Workstation-to-Workstation" -Direction Inbound -Action Block

      • Use tools like OSSEC for host-based intrusion detection:

        ossec-logtest

  • Detection at the Endpoint Level:

    • Leverage antivirus systems and EDR solutions to detect malicious activity on endpoints:

      • Example EDR query in Microsoft Defender for Endpoint:

        Get-MDATPDevice -DeviceName "CompromisedHost"

      • Enable Attack Surface Reduction (ASR) rules to block common attack techniques:

        Add-MpPreference -AttackSurfaceReductionRules_Ids <RuleID> -AttackSurfaceReductionRules_Actions Enabled

  • Detection at the Application Level:

    • Analyze application and service logs for signs of compromise:

      • Example Splunk query to detect unusual login attempts in web server logs:

        index=web_logs status=401 | stats count by src_ip

      • Monitor database logs for unauthorized queries:

        SELECT * FROM mysql.general_log WHERE command_type = 'Query' AND argument LIKE '%DROP TABLE%';

---

3. Initial Investigation

Purpose: To gather sufficient information about a detected incident before escalating the response.

• Why: Jumping to conclusions without proper context can lead to unnecessary escalations or missed critical details. A thorough initial investigation ensures accurate understanding and prioritization.

• Technical Example:

  • Establish Context:

    • Investigate alerts by correlating multiple data sources:

      • Example SIEM query to correlate firewall logs with endpoint events:

        index=firewall_logs src_ip="192.168.1.100" | join transaction_id [search index=endpoint_logs]

      • Verify the system associated with an IP address and time zone:

        nslookup 192.168.1.100
        date +"%Z %z"

  • Collect Information:

    • Gather details from various sources:

      • Employee Reports: Document abnormal behavior observed by employees.

      • Tool Alerts: Review alerts from EDR, IDS, firewalls, or SIEM systems.

      • Threat Hunting: Proactively search for indicators of compromise (IOCs):

        Get-WinEvent -LogName "Security" | Where-Object { $_.Id -eq 4624 }

      • Third-Party Notifications: Validate external reports of compromise.

---

4. Information Sharing and Threat Intelligence

Purpose: To leverage context-based threat intelligence and share knowledge across teams for faster and more effective responses.

• Why: Threat intelligence provides valuable insights into emerging threats and attacker tactics, helping organizations stay ahead of adversaries.

• Technical Example:

  • Integrate Threat Intelligence Feeds:

    • Use threat intelligence platforms like MISP, AlienVault OTX, or VirusTotal to enrich detection capabilities:

      • Example VirusTotal API query to check a suspicious file hash:

        curl -X GET "https://www.virustotal.com/api/v3/files/<FILE_HASH>" -H "x-apikey: YOUR_API_KEY"

    • Feed IOCs into SIEM systems for real-time correlation:

      index=threat_intel ioc="malicious_domain.com"

  • Share Findings Across Teams:

    • Use collaboration tools like Slack, Microsoft Teams, or Jira to document and share findings:

      • Example Slack notification for a detected threat:

        curl -X POST -H 'Content-type: application/json' --data '{"text":"Suspicious activity detected on Host X"}' https://hooks.slack.com/services/YOUR_WEBHOOK_URL

---

Conclusion

The detection and analysis phase is critical for identifying and responding to security incidents effectively. By implementing a layered detection strategy, conducting thorough initial investigations, and leveraging threat intelligence, organizations can improve their ability to detect and respond to threats.