I am running Ubuntu 13.04 with KDE. Today, Software update notification indicated security updates containing updates to libfs6, libx11-6, libx11-data, etc.
When proceed with the updates, it asks for my password and then gives a message:
The following pieces of software cannot be verified. WARNING: Installing unverified software represents a security risk, as the presence of unverifiable software can be a sign of tampering. Do you wish to continue/ cancel
I have, of course, canceled updates. What could be the issue/ how do I set it right? More importantly, is my system hacked/ compromised?