Avira Antivirus update cripples millions of Windows PCs


Emil Protalinski


German security company Avira is experiencing serious technical difficulties. A defective antivirus update that has been downloaded millions of times is bringing Windows XP, Windows Vista, and Windows 7 computers to a screeching halt across the world, according to user reports (1, 2).

The update bumps the software version to and the definitions file to The result is that the AntiVirProActiv component starts detecting critical processes as malware, including the following:

Those are just some of the false detected Windows processes. Avira sometimes kills them and stops Windows from booting, but that’s not the end of it.

The update is also blocking other Microsoft software (such as Microsoft Office and Microsoft Works) as well as various third-party applications, including Byki 4 Express, Documents To Go, Garmin, Google Talk, iPod and Palm services, Opera, OpenDNS Updater, Polipo, Shadow, Stickies, and many others. In other words, almost every executable file is being falsely detected by this update.

The good news is that the free edition (Avira AntiVir Personal) does not include ProActiv, so it is not affected. The bad news is that the paid consumer editions (Avira Antivirus Premium and Avira Internet Security) as well the business edition (Avira Professional Security) do have it, and thus are affected.

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