Defense & IR · medium · solved in-browser (no VM needed) · 3 tiered hints
Write /etc/sysctl.d/99-kernel-hardening.conf to reduce kernel exposure. Force full address-space randomization (kernel.randomize_va_space = 2), restrict kernel pointer exposure (kernel.kptr_restrict = 2), restrict the kernel ring buffer (kernel.dmesg_restrict = 1), and block setuid core dumps (fs.suid_dumpable = 0). (Authored config, graded structurally — the engine isn't run here.)
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Incident response: evict rogue accounts, eradicate persistence, attribute a breach.
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