The Arch Linux project has confirmed that its core infrastructure has been under sustained DDoS attack for more than a week. The campaign, which began on August 16, 2025, has disrupted user access to the project’s main website, the Arch User Repository (AUR), and the community forums. Service interruptions remain ongoing, with many users reporting intermittent connectivity and degraded performance.
What is Arch Linux?
Arch Linux is a lightweight, rolling-release Linux distribution that gives users full control over their system. Instead of shipping with preconfigured defaults, it provides a minimal base that can be customised to fit specific needs. Software is delivered through official repositories and the Arch User Repository (AUR), a large community-maintained package collection. Arch is widely used by experienced Linux users and system administrators who value flexibility, transparency, and up-to-date software.
Technical Characteristics of the Attack
The Arch Linux DevOps team has described the incident as a volumetric Layer 3/4 flood. Attack traffic has saturated available bandwidth and exhausted server resources, overwhelming the project’s hosting environment. The disruption has been most visible to users as TCP SYN resets on initial connection attempts. In many cases, subsequent retries succeed, but latency and reliability remain inconsistent.
Mitigation measures deployed to date include TCP SYN authentication provided by the hosting provider, as well as emergency rate limiting and selective traffic filtering to reduce malicious flows. The team has also relied on geo-distributed mirrors to ensure that key downloads such as installation images remain available. Coordination with upstream providers is ongoing, and the project has confirmed that it is evaluating commercial DDoS protection solutions. However, as a volunteer-driven project, Arch Linux emphasised that any long-term decision must balance cost, technical efficacy, and ethical considerations.
Service Impact and User Workarounds
While the main Arch Linux domains remain partially degraded, the project has published recommended workarounds to maintain continuity of operations. These include alternative mirror endpoints for packages and ISOs, GitHub-hosted AUR mirrors, and offline snapshots of the Arch Wiki.
| Affected Service | Alternative Endpoint / Mirror | Access Instructions |
|---|---|---|
| archlinux.org main site | Default mirror list from pacman-mirrorlist package | Use reflector or manually update /etc/pacman.d/mirrorlist with entries from pacman-mirrorlist. |
| Installation ISOs | Geomirror archive (https://geo.mirror.pkgbuild.com/iso/) | Download ISO and verify signature with key 0x54449A5C. |
| aur.archlinux.org | GitHub AUR mirror (https://github.com/archlinux/aur) | git clone --branch <pkg> --single-branch https://github.com/archlinux/aur.git <pkg>. |
| wiki.archlinux.org | arch-wiki-docs or arch-wiki-lite snapshots | Use offline snapshots or static mirror repositories. |
Arch Linux has urged users to verify their mirror configurations and leverage these fallback mechanisms until primary services are fully restored.
Ongoing Response and Next Steps
To maintain transparency, the project has launched status.archlinux.org as its official communications channel for real-time updates. Automated health checks have been implemented to provide visibility into the availability of the website, AUR, forums, and supporting infrastructure.
Forensic data and log collections are being preserved for post-incident analysis. The project has stated that a comprehensive post-mortem will be published once the attack subsides. This report is expected to include root cause analysis, details of the mitigation effort, and potential attribution if feasible.
Despite limited resources, the Arch Linux team has impressively maintained essential functionality through mirrors and fallback endpoints, while working with providers to contain the impact of the attack.
About FastNetMon
FastNetMon is a leading solution for network security, offering advanced DDoS detection and mitigation. With real-time analytics and rapid response capabilities, FastNetMon helps organisations protect their infrastructure from evolving cyber threats.
For more information, visit https://fastnetmon.com