← Courses

Defensive Security Essentials

Cybersecurity

Detecting and Responding · Lesson 9 of 11

Reading logs like an analyst

The system keeps a diary

Every serious system keeps logs: records of who did what and when. Logs are how an analyst spots an attack, often the only trace it leaves.

A login log might look like this. Run the code to count the failed attempts:

Python

Three failed logins for "admin" in a row is a warning sign: someone may be guessing the password. An analyst watches for exactly these patterns: many failures, odd hours, or logins from far away.

Exercise

Exercise — check your understanding

Given the list logins, count how many entries are failures (they start with "FAIL") and store the number in fail_count.

You’re reading for free. Sign in to keep your progress and earn a certificate when you finish.Sign in to keep my progress →