Log Analysis and Security Information Management
Log analysis is the foundation of any effective threat detection strategy. Every IT system generates millions of events a day, from servers, firewalls, endpoints, applications and databases, and the ability to collect, normalize, correlate and analyze this data in real time is what separates a resilient organization from a vulnerable one.
The Role of Log Analysis in Modern Cybersecurity
Log analysis in cybersecurity goes well beyond simply archiving logs. It is a structured process that turns raw data into actionable intelligence, allowing security teams to identify anomalous patterns, reconstruct the attack chain during an incident and demonstrate compliance with regulations such as GDPR and NIS2.
Fidem integrates log analysis into its managed SOC, using the proprietary Defensio engine for event correlation and the multi-stage AI pipeline to classify anomalies, with final control by the analysts.
Service Architecture
Collection and Normalization
We deploy dedicated collectors for every type of source: syslog for network devices, Windows Event Log for endpoints, application audit logs, flow data (NetFlow/sFlow) for network traffic. All data is normalized into a unified format to allow cross-source correlation.
Correlation and Detection
The Defensio correlation engine applies static (signature-based) rules, behavioral analysis (baseline deviation) and machine learning models to identify threats. Rules are aligned with the MITRE ATT&CK framework to ensure full coverage of adversary tactics and techniques.
AI-Based Anomaly Detection
Event triage follows the multi-stage AI pipeline of the Defensio ecosystem: a machine learning model first filters out the noise and the benign mass of events, then specialized language models running on-premise analyze the complex cases in depth, with independent cross-validation before the alert reaches the analyst. The result is far fewer false positives, without losing sensitivity.
Archiving and Compliance
Logs are archived in compliance with regulatory requirements (GDPR Art. 30, NIS2), with configurable retention policies, encryption at rest and a verifiable chain of custody. The platform supports automatic generation of reports for compliance audits and forensic investigations.
For system administrator logs, which the Italian Data Protection Authority’s provision and the NIS2 measures require to be complete, unalterable and verifiable, Fidem delivers a dedicated service: Custos, with cryptographic sealing, timestamping and an evidence package for inspections.
Integration with the Fidem Ecosystem
Log analysis is a fundamental component of the Threat Detection service and integrates natively with the other Fidem services:
- Defensio Sensor: the passive network probe installed in the company network, which adds network telemetry and asset inventory to the logs, to correlate events with what happens on the network
- Defensio XT: provides Attack Surface Management data for external correlation
- Vulnerability Assessment: VAPT findings are correlated with operational events
For an initial assessment of your log management needs at no cost, contact us.
What is log collection for?
Logs are there to answer a question that always comes afterwards: what happened, when, and who was there. Without central collection, that answer does not exist, because the data sits on different machines, with different clocks, and is overwritten within days.
How long should logs be kept?
Retention time is the variable that decides whether an incident can be reconstructed. An attack is discovered on average long after the initial intrusion: if logs cover thirty days and the initial access happened three months earlier, the analysis starts blind. The window should be chosen on the typical time to discovery, not on disk space.
Log analysis or SIEM: what is the difference
SIEM is the technology that collects and correlates; log analysis is the work of reading the logs. Buying one without doing the other produces an archive nobody queries. Continuous oversight is the managed SOC.
What it does NOT solve
Logs record, they do not prevent: prevention remains the job of endpoint protection and email security. And a log is not evidence in itself: to stand up in court it needs acquisition with chain of custody, which is the work of a digital forensic examination. Terms defined in the glossary.