HardStacked blogLinux hardening, measured and reversiblehttps://hardstacked.net/blog/2026-07-20T12:00:00ZHardStackedFive green lights that lied: anatomy of a routine Linux checkuphttps://hardstacked.net/blog/green-lights2026-07-20T12:00:00ZA routine checkup on a hardened Linux box ended all green, but five reassuring signals were traps on the way: the empty grep, the free-memory panic, the service that was never down, the fresh file with a stale number, and the score that says nothing about who rattled the handle.Microsoft scores an F, my blog scores an A: what a security grade really measureshttps://hardstacked.net/blog/security-badge2026-07-20T12:00:00ZWe scanned microsoft.com, facebook.com and our own static blog on securityheaders.com: an F, an A and an A. The reasons behind each grade say more about incentives than about competence.Locked out of your own VPS: the 5 classic SSH lock-outshttps://hardstacked.net/blog/ssh-lockout2026-07-19T12:00:00ZFive mistakes lock people out of their own servers: password login off without a tested key, the firewall before the allow rule, fail2ban banning you, the port change systemd ignores, and the typo that explodes weeks later.Raising your Lynis hardening index: what actually moves the scorehttps://hardstacked.net/blog/lynis-score2026-07-19T12:00:00ZWe measured a Lynis climb fix by fix: the 25-point penalty apt upgrade leaves behind, why installing security tools earns nothing, and four rules for an honest score.1234 login attempts in 41 hours: who really knocks on an exposed SSH porthttps://hardstacked.net/blog/invalid-user2026-07-19T12:00:00ZWe counted every SSH probe against a quiet test box: 1234 attempts on accounts that do not exist, 132 usernames, 93 IPs, activity around the clock. What the logs say about who is knocking.