How can you use log analysis for effective security incident investigation?

I think that the main challenge is to decide what type of logs should be recorded. It is quite hard and expensive to opt for "log all", so first of all its necessary to define what type of log makes sense. Secondly, I would say: Know your operational system! For example, Windows has a lot of tricks when it comes to logging. Some crucial options, for example, cmd logging are not registered by default, so if you know what to log and how to enable that specific logging, you will succeed during an incident response.

Recomendo o uso de soluções como SIEM por serem altamente eficientes na captação de logs, normalização como dados e ainda permitem acompanhamento e resposta para incidentes de segurança preventivamente.

Imagine a trail of breadcrumbs (like suspicious logins or file changes) leading you to the culprit. Analyze logs across systems (servers, firewalls, applications) to piece together the timeline, identify compromised machines, and understand the attacker's tactics. Think of it as a detailed crime scene report. By correlating events, spotting anomalies, and identifying patterns, you can: Pinpoint the attack vector: Was it malware, phishing, or a brute-force attempt? Reconstruct the attacker's movements: Track their lateral movement within your network. Assess the damage: Identify affected systems and data. Inform future defenses: Learn from the incident and strengthen your security posture.

Log analysis plays a crucial role in enhancing security measures and incident response. Here are key advantages of log analysis: Real-Time Visibility: Enables real-time monitoring of network activities, helping detect and respond to security incidents promptly. Anomaly Detection: Identifies unusual patterns or behaviors in log data, serving as an early warning system for potential security threats. Incident Reconstruction: Assists in reconstructing the sequence of events during a security incident, aiding in understanding the attack's origin and progression.

The log will always be your trusted partner in the incident response process. It will help you correlate certain behaviors, such as an endpoint that started a certain process when a user clicked a link and, unbeknownst to the user, downloaded and executed something on the machine that could be fileless malware. -Endpoint processes that may have been created and run through PowerShell. -Abnormal use of PowerShell and WMI outside of casual activity; -Network traffic behind communications outside of your network's ips pattern. These are some important logs that need to be analyzed and correlated to understand if there is anything that could compromise an endpoint. Yes, the log is essential to any incident response process.

I think it's about understanding what's actually being done. For example, if I am analyzing a Windows process that might be compromising an endpoint. What do I need to understand in order to correlate? For example: -Understand the system - Determine if smss.exe and csrss.ex were run next; -wininit.exe and services.exe were also started in some way. The difficulty I see and experienced early in my incident response career was understanding how different processes work and what they can do to really understand if it's legitimate or not. But it takes a lot of study and experience to get that understanding.

With numerous interconnected systems/infrastructure used by enterprises (public/private cloud, on premise), the variety of logs generated and collected is complex. And often during Incident response SOC teams spend a lot of time in triaging the logs to find relevant information such as IOCs (Indicators of Compromise) to eradicate and recover the system(s) affected. Another key challenge is for forensic analysts to derive incident timeline given the complexities involved in log analysis. All of these result in significant damage to the organization (data exfiltration, persistent access and system availability).

From what we've seen in our past experience, you must be curious. So whenever you perform an analysis, you must try to always go a level deeper to understand the source of the information. For example, an IP address blocked a suspicious email. Find who sent the email, then isolate the email to be able to open it. Then, you open the advanced properties to get more data. From there, you are able to see it's DMARC score, for example. You can then open an email analyzer to find the source of this email. This kind of methodology can be extrapolate to any log analysis scenario.

Completing lab exercises is really important to improving your log analysis skills, specifically blue team/defense focused exercises using hackthebox, tryhackme etc. Keeping updated on the latest cybersecurity attack techniques and vulnerabilities by reading popular security focused sources such as MITRE ATT&CK, Krebsonsecurity, Bleepingcomputer and the tenable blog will help improve log analysis using pattern recognition.

If the right data is not aggregated and correlated from the beginning, it can become cumbersome when trying to find the needle in the haystack. Try to kill as much noise as possible without losing context by setting the right logging levels. Threat Intelligence provides a lot of context. Let's say you're a security analyst responsible for monitoring the logs of your organization's network devices. You notice an unusual pattern of traffic in the firewall logs, indicating a series of connection attempts from an IP address that hasn't been seen before. Threat intelligence can not only tell you the IP's reputation, but can also help you attribute the attack to a threat actor.

Log analysis is integral to cybersecurity, yet it comes with challenges, 1. The sheer volume of logs, often noisy with false positives, can overwhelm analysts. 2. Sophisticated threats may go unnoticed, as traditional methods struggle to detect advanced techniques. 3. Resource-intensive log management poses difficulties, particularly for organizations with limited resources. 4. Logs lack context, requiring correlation from various sources for a comprehensive security understanding. Organizations must be aware of these challenges and consider augmenting log analysis with measures like threat intelligence integration and behavioral analysis for a more strong security posture.