‼️🚨 The official JDownloader website was breached, attackers swapped the Windows and Linux installers with malware for over a day before anyone noticed.
JDownloader is a popular download manager with millions of users on Windows, macOS, and Linux.
Timeline:
▪️ May 5, 23:55 UTC: attacker tests the method on a dummy page.
▪️ May 6, 00:01 UTC: real attack goes live. Alternative download links for Windows and Linux are replaced with malicious installers.
▪️ May 7: a Reddit user notices Windows SmartScreen flagging the installer with a strange publisher ("Zipline LLC", "The Water Team", "Peace Team") instead of "AppWork GmbH".
▪️ Hours later, the JDownloader dev team confirms the breach and takes the site offline.
How they got in: an unpatched vulnerability let attackers modify the website's access control list (ACL), give themselves edit rights, and swap the download links. No further details on the bug have been shared.
What's compromised:
▪️ Windows installer (alternative download links).
▪️ Linux shell installer (alternative download links).
What's safe:
▪️ macOS installers (still validly signed).
▪️ The core JDownloader.jar file.
▪️ Flatpak, Winget, and Snap packages (separate infra, sha256 checksums unchanged).
▪️ In-app auto-updates (separate servers, end-to-end signed).
If you downloaded JDownloader from the website between May 6 and May 7, treat your machine as compromised.
This is the third trusted-software website breach in recent weeks, after Daemon Tools and CPU-Z / HWMonitor.