Avira Antivir Professional
Avira Antivir, if you can get past the ugly avoided name, live in natural shade from the command line, though it does require real knowledge Bash to install or use. Download the archive and run the install script in to arrange everything. There follow a series of questions about the options that will be installed, whether to use a service scan-on-access and where you've put Your keyfile. The latter is the only obstacle on the installation.
For reasons still unclear, the site provided us with the key to the hearing, but to no avail. If you have the same problem, pretend you live in the United States.
Once we have installed, we see the existence of a configuration file and automatically installed daemon to run software on startup.
Run the test scan surprise – the software seems at once, and barely taking any memory or CPU cycles at all. It would be easy to believe that nothing happened, but scanners identify all infected files and offer to quarantine them.
The default setting seems pretty good and virus database is kept up to date as well, so you don't need to be afraid that you have to be extra vigilant in the configuration. It works impressively quickly – it's just a shame that the scan-access is not available to the kernel.
Avira has no free version of the antivirus software, but all versions of Linux are under a professional Department, so there is no exemption if you non-business users. That said, don't make a costly license structure: £25 for the one-year licence for a single user.