InfraGuard

Detection rule: Wrong-direction First Data

First data flowing in the opposite direction to expectation.

WarningProtocol AnomalySuricata

What it detects

First data flowing in the opposite direction to expectation.

Why it fires

Possible abnormal client/server implementation or protocol abuse.

Worst case

Protocol abuse

Matching signatures

wrong direction first data

Track these versions on your own servers

InfraGuard collects installed software versions from every server and flags the ones with known vulnerabilities. Self-hosted — nothing leaves your network.

Weekly exploited-vulnerability digest

The KEV additions that matter for self-hosted servers, once a week. No other mail.