How to detect abnormal data leakage behavior through log analysis?

Detecting abnormal data leakage behavior through log analysis involves monitoring, analyzing, and identifying unusual patterns in system logs that may indicate unauthorized data access or exfiltration. Here’s a step-by-step approach with examples and recommended Tencent Cloud services:

1. Collect Comprehensive Logs
   Gather logs from various sources, including servers, databases, applications, and network devices. Logs should include access timestamps, user IDs, IP addresses, requested resources, and data transfer sizes.

   • Example: A database log shows repeated queries accessing sensitive customer records by a non-admin user.

2. Establish Baselines
   Define normal behavior patterns using historical logs. This helps identify deviations.

   • Example: A user typically accesses 100MB of data daily, but suddenly downloads 10GB—this is a red flag.

3. Analyze for Anomalies
   Use log analysis tools to detect unusual activities, such as:

   • Unusual Access Times: Logins or data access outside normal working hours.
   • Excessive Data Transfers: Large volumes of data being downloaded or transferred.
   • Unauthorized IP Addresses: Access from suspicious or foreign locations.
   • Example: A sales employee accesses financial databases, which they normally don’t use.

4. Correlate Logs Across Systems
   Combine logs from multiple systems to trace end-to-end activities.

   • Example: A user logs into the VPN, accesses the database, and then uploads files to an external server—indicating potential exfiltration.

5. Automate Detection with Alerts
   Set up real-time alerts for suspicious activities using Tencent Cloud Cloud Log Service (CLS) and Security Center. These tools can parse logs, detect anomalies, and notify administrators.

6. Investigate and Respond
   Once an anomaly is detected, investigate further by correlating logs, checking user permissions, and reviewing network traffic. If confirmed as a leak, take immediate action (e.g., revoke access, block IPs).

Tencent Cloud Services Recommendation:

• Cloud Log Service (CLS): Centralized log collection, storage, and analysis.
• Security Center: Threat detection, anomaly alerts, and compliance monitoring.
• Tencent Cloud Database Audit: Tracks database access and identifies risky operations.

By leveraging these tools, organizations can proactively detect and mitigate data leakage risks.