# Tweet by [@keefmoon](http://twitter.com/keefmoon) on 2009-09-03 22:07:58 > [!INFO] Archived from [original tweet](http://twitter.com/keefmoon/status/3743209444) In reply to: [@keef319](http://twitter.com/keef319/status/3742438473) @keef319 In Linux, each file has to be explictly set to be executable. So a virus could not run itself without user intervention.