Hack the Route Start free Open app Detection and response
IDS signatures and alerts
A rule describing a known attack in the traffic's content; the IDS alerts (or, inline, drops) whatever matches.
A Suricata or Snort rule has an action (alert, drop, reject, pass), a protocol, source and
destination, and options: msg for the alert's text, what to match and where (content:"/etc/passwd" in
http.uri), and a sid (its number; 1000000 and up for your own) with a rev (its version). Signature-based
detection finds known attacks precisely and misses new ones; anomaly-based detection flags what departs from a
baseline, catching the new at the price of more false positives. Alerts go to a human-readable log (fast.log) and a
machine-readable one (eve.json, JSON lines a SIEM ingests). Tuning makes a noisy rule specific, suppresses it
for a known source or thresholds it, so the alerts that remain are read.