cannot update security

[Ekaterina]

Can't install programs in terminal
Sorry, command-not-found has crashed! Please file a bug report at: https://bugs.launchpad.net/command-not-found/+filebug Please include the following information with the report: command-not-found version: 0.2.44
When I update the system, this shows:
W:Failed to fetch http://deb.torproject.org/torproject.org/dists/precise/InRelease Unable to find expected entry 'main]/source/Sources' in Release file (Wrong sources.list entry or malformed file)
During update in terminal
 E:Some index files failed to download. They have been ignored, or old ones used instead.
Cannot access the user accounts window, appears for 1 second and disappears.
security updates don't work.

[Ekaterina (katekou)]

E:Type 'http://archive.ubuntu.com/ubuntu' is not known on line 2 in source list /etc/apt/sources.list
major problem
I am new to ubuntu

[Marc Deslauriers (mdeslaur)]

Thanks for taking the time to report this bug and helping to make Ubuntu better. We appreciate the difficulties you are facing, but this appears to be a "regular" (non-security) bug. I have unmarked it as a security issue since this bug does not show evidence of allowing attackers to cross privilege boundaries nor directly cause loss of data/privacy. Please feel free to report any other bugs you may find.