timppu: Do the Avira and Norton equivalents also download the latest virus definitions, or do they expect you to re-burn a new CD-RW each time with the latest definitions?
chadjenofsky: What's nice about Avira - The rescue disk comes preinstalled with the latest definitions. This allows someone to disinfect a system without it being connected to the Internet and also without the system's OS being booted. I don't recall an option to check for updates, but this would defeat the purpose, I think.'
I'd like it to have the best of both worlds: the rescue disc includes the latest definitions (for the day you downloaded and burned it), but on top of that it would have the option to check for the latest virus definitions online after booting with it. I think the Kaspersky rescue disc did have an updated virus definitions on the image, not sure how often they update it.
After all, sometimes new virus definitions seem to come several times a week, so your burned rescue disc would become outdated quite fast, without the option to check for the latest definitions when you actually use it.
EDIT: Not sure if Kapersky still maintains it or not. Many months ago i got the impression somewhere that Kaspersky doesn't maintain it anymore (a bit like GOG doesn't maintain the legacy GOG Downloader anymore, but isn't blocking its usage either), but I don't see any indication of that on their page though:
http://support.kaspersky.com/4162 It seems though the CD image has been dated to October 2014, so the included virus definitions are probably quite old. So, it is a good idea to have the PC to be scanned be connected to internet (either with a LAN cable in which case it connects automatically when you boot with the rescue disc, or if using protected WiFi, you need to connect it after you have booted).
The reason I started looking for these bootable virus scanners is because when the Security Sphere 2013 malware hit one of my computers years ago, it made pretty much all virus scanners non-functional (including Avira which was installed already, it somehow prevented it from working anymore). Maybe I was able to run Malwarebytes in safe mode or something, but it couldn't get rid of the problem anyway.
So yeah, I want a secondary scanner that can be booted up on its own, preferably to a non-Windows environment. Just to make sure those malwares can't affect it at least directly. I guess I'll keep the Kaspersky Rescue Disc available. Maybe I'll check the Avira one also, just in case.