What it is
File-sharing ports: SMB, NFS, FTP, rsync.
Why it is risky
Internet exposure is a conduit for ransomware spread and data leakage; SMB is a perennial worm target (EternalBlue-class).
What to do
Restrict to internal networks / VPN, apply least-privilege shares and patches, and replace FTP with SFTP.
Is it listening on your server?
Linux
ss -ltnp 'sport = :139'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.