The Ultimate Hosts Blacklist is a unified hosts file project designed to protect networks, computers, smartphones, and Wi-Fi devices against malicious websites and threats. The repository maintains one of the world's largest curated blacklists, aggregating information from multiple sources and merging it into comprehensive blocking files updated daily. As of the documented version, the project contains 922,245 bad domains in its main hosts file, 148,793 bad IPs in the hosts.deny file, and 1,071,038 combined entries in the superhosts.deny file.
The project operates through a distributed infrastructure with multiple file formats and delivery methods to accommodate different use cases and operating systems. The core hosts file is available in both Unix and Windows formats, with additional specialized formats including hosts.deny for Unix/Linux systems, superhosts.deny for comprehensive blocking, domains.list for Pi-Hole compatibility, domains-dotted-format.list for DnsMasq, and ips.list for IP-based blocking. All files are updated daily and distributed through a central GitHub repository, an official mirror at hosts.ubuntu101.co.za, and through dedicated DNS servers.
For users who prefer not to manage hosts files locally, the project provides two DNS servers operating at safedns.allover.co.za and safedns2.allover.co.za, available on ports 53 and 5353 for both IPv4 and IPv6 connections. These DNS servers implement the same blocking logic without requiring local file management and are explicitly recommended for Windows users. The DNS servers maintain no logging and operate continuously with scheduled maintenance windows never affecting both servers simultaneously.
The repository provides platform-specific installation, update, and uninstallation scripts written in Shell for Linux and batch files for Windows. Linux users have access to separate installers and updaters for the hosts file, hosts.deny file, and superhosts.deny file. Windows users receive dedicated installation, update, and uninstallation scripts, though the project recommends DNS server usage over local hosts file installation on Windows systems.
The project's scope extends beyond traditional malware and ransomware blocking to include protection against adware, clickjacking, and content categories such as adult material, drugs, alcohol, and violence, making it suitable for family protection scenarios. The hosts file approach works by mapping listed domain names to localhost addresses, preventing outbound connections to blocked domains. Since hosts files take precedence over DNS queries on most operating systems, blocked requests never leave the user's device.
Community engagement is structured across multiple GitHub repositories within the Ultimate-Hosts-Blacklist organization. Users can report issues, submit discussions, and request domain additions or removals through designated repositories. The blacklist repository handles domain and IP additions, while the whitelist repository manages removal requests. Infrastructure-related discussions and issues are directed to the dev-center repository. The update schedule follows a consistent UTC-based timeline, with the central repository updating around 19:05 UTC, the official mirror updating at 19:30 UTC, and DNS servers completing synchronization by approximately 19:40 UTC daily.
