Guidance on Windows and Linux brute-force prevention, RDP, Exchange, failed-logon evidence, source attribution, trusted-source learning, shared reputation, Custom Monitors, Datacenter and the operational lessons behind Scantide Guard.
Account lockout protects an identity. It does not stop the source generating the failures, and it can itself be abused to deny service. Host-based source blocking solves a different part of the problem.
Reduce unnecessary exposure, monitor Windows authentication evidence, block hostile sources locally, detect slow attacks, and centralize policy as the server estate grows.
Protect RDP, RemoteApp and RDWeb by combining controlled exposure, Windows authentication evidence, realistic thresholds, trusted-source learning and application-aware monitoring.
Internet-facing mail authentication can be used for credential guessing and for deliberate account lockouts. Source-based blocking adds protection without disabling the identity being targeted.
Low-and-slow attacks deliberately stay below burst thresholds. Longer observation windows, repeat-offender handling and reputation context help reveal persistent sources.
Manual firewall blocks can stop one source, but distributed and recurring authentication attacks require automation, provenance, expiry and policy.
Unexpected authentication failures inside a LAN can reveal malware, stale credentials, misconfiguration or lateral movement. Broad internal whitelisting can hide exactly the evidence you need.
A failed-logon event is only safe for source blocking when the actual attacker address is available. RDP, RDWeb, NTLM, gateways and proxies can change what Windows records.
Failures tell you who is being rejected. Successful authentication helps distinguish legitimate administration, learn trusted sources and understand whether a credential attack may have succeeded.
Interactive, network, remote-interactive and service logons are operationally different. Understanding logon type helps interpret failed-login events and avoid bad blocking decisions.
A web application's apparent source can be the reverse proxy rather than the real client. Forwarded headers are useful only when Guard knows which intermediaries are trusted.
RDP, SQL, SMTP, web applications and custom software have different normal authentication behavior. Per-monitor policy lets Guard respond without forcing one global threshold everywhere.
Install protection where there is meaningful authentication or application evidence and real exposure. Not every machine needs the same security agent.
Verify logging, firewall state, source attribution and normal authentication behavior before enabling aggressive automatic blocking.
For unfamiliar applications and Custom Monitors, observe events first, validate parsing and baselines, then enable enforcement with confidence.
Perimeter firewalls reduce exposure; host-based protection sees the authentication evidence. The strongest design uses both rather than treating them as competitors.
Security agents collect valuable history, but unbounded event databases eventually become an operational problem. Retention, rollover and centralization are part of reliable security design.
Older Windows Server systems still exist in production. Supporting them safely means isolating compatibility code while continuing to modernize the main product.
Local attack evidence becomes more valuable when it can warn other servers, but shared reputation needs provenance, controlled publishing, caching and false-positive safeguards.
A firewall block stops immediate traffic, but the event can also support incident review, abuse reporting, threat correlation and longer-term hardening.
GeoIP, abuse reputation, global blacklists and external intelligence lose value when they stop being updated. Stale security context can be worse than clearly unavailable context.
Local enforcement is valuable, but fleets need central policy, shared monitors, license visibility, reputation caching and cross-server context.
Not every failed login means someone selected your organization specifically. Usernames, timing, recurrence and cross-server patterns help distinguish generic scanning from more targeted behavior.
Built-in collectors provide immediate coverage. Custom Monitors extend the same event, policy and blocking model to your own applications and log formats.
A security control may keep running while its assumptions, intelligence, compatibility and dependencies quietly age. Active maintenance is part of the security model.
More than a decade of operational experience shaped Guard around maintainability, event quality, custom monitoring, successful-login learning, central management and live reputation data.
If you are looking for the product rather than the technical background, start with the Guard overview, download the current installer and use the guides when you need the deeper reasoning.
Scantide GuardSupported operating systems