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Ask Slashdot: Protecting Home Computers From Guests?
An anonymous reader writes "We frequently have guests in our home who ask to use our computer for various reasons such as checking their email or showing us websites. We are happy to oblige, but the problem is many of these guests have high risk computing habits and have more than once infested one of our computers with malware, despite having antivirus and the usual computer security precautions. We have tried using a Linux boot CD but usually get funny looks or confused users. We've thought about buying an iPad for guests to use, but decided it wasn't right to knowingly let others use a computing platform that may have been compromised. What tips do you have to overcome this problem, technologically or otherwise?"
I think they call it guest wifi and byod.
> We are happy to oblige, but the problem is many of these guests have high risk computing habits and have more than once infested one of our computers with malware,
Really? It's not that they started typing something into your browser and the browser history showed off all the sick and twisted porn you watch? :P
I'm god, but it's a bit of a drag really...
Have a dedicated Linux boot just for them, and if they give you funny looks tell them too bad.
Set up a VM in Virtual Box for them to use. Take a snapshot of when it was healthy and new and just revert to that each time someone wants to use it. Even paying for a Windows install for the VM would be cheaper than an iPad.
Something like VirtualBox or VMWare that supports snapshots. Install an OS into the virtual machine and set some firewall rules to keep it from accessing anything else on your network. When they ask to use your computer, launch the virtual machine and set it to full screen. They won't know the difference. When they're done, revert to snapshot.
Sound like a good use for a Chromebook.
Get smarter guests
The media PC in my living room boots directly into the Guest account. Under the guest account I can USE almost all the programs I have installed seamlessly. There are some minor issues with software updates, XBOX controllers, and a complete inability to configure network settings, but that's about it. If I need to do anything that requires more rights I can deal with the UAC prompts that show up or simply log out and back in as an admin.
I know it's not flawless but I still feel pretty comfortable letting my tech savvy (e.g. dangerous) friends stay over unattended. It wouldn't hold up to anyone seriously determined to break the security but they have access to the physical machine and can't really be stopped anyway.
I don't even tell people where I live.
I consider myself to usually be on the bleeding edge of technology, but phone-based boarding passes are right out. I've never had a piece of paper run out of power, but I've had my phone die halfway through the travel day for reasons unknown (turned into a little toaster and burned through its battery - presumably the radio got in a weird state) and have had it stolen while traveling. I keep two boarding passes, typically - one folded in my pocket, and one in my carry-on. If I lose one, I just grab the other one.
And yes, most of the time when my guests want to borrow a machine, it's because they need a printer for boarding passes.
There was a time in the distant past that I built a "very special" win9x machine for this very purpose.
Yes, I can read your mind. "Win9x? Are you fucking serious? Turn in your geek card right now!" Yadda, yadda.
Just hear me out.
Win9x, because it relies on realmode dos interrupt disk handlers, can be loaded from a preboot environment ram only block device. Such as that provided by Memdisk, from the syslinux tool set.
Essentially, you have a disk image file on a bootable EXT2 volume (nothing ever gets written on it, so it doesn't need a journal.) With the syslinux bootloader on the MBR. It is the default boot device.
On boot, syslinux starts, loads the memdisk block device driver, and copies the win9x image into ram, it patches int15 to report a different max size of installed XMS, then executes the "mbr" of the ram block device.
BOOM. Win9x in a ramdisk.
You can use a drivespace compressed image to achieve maximum data density for the consumed block of memory. Drivespace3 with ultrapack on gets almost 2:1 packing on normal program and file data. You can get a *lot* of stuff inside a 512mb image file.
Throw in a reasonably recent firefox, courtesy of KernelEx (an open source kernel resource extender for win9x, which allows a good deal of 2k and XP native applications to run, including FF10, and a modern flashplayer with ABP and noscript.) And a good software firewall, turn off all filesahring services, and essentially lock down the 9x system as far as possible, and you have exactly what your horrible family member and or aquaintence wants: a familiar user environment that they can walk all over.
It also has what you want: pull the plug, and it is magically fresh, clean, shiny and new again as soon as you power it on.
9x doesn't know how to deal with EXT filesystems, so the physical HDD is never exposed to your user.
The only major problems are 9x's abhorrent 2gb RAM limit, and its abysmal network safety rating, coupled with its rather dated hardware base. (Plus the difficulty of getting a 9x install up and running smoothly with all the perks a normal user could want, without breaking it, on a teensy weensie volume.)
On the plus side, being 100% in RAM on a reasonably modern hardware platform, it is fast as fuck. The test systems I built had Office97, firefox 10, flashplayer10, the WEP, a pirate copy of zonealarm pro, photoshop7, media player 10, KernelEx, and a few other odds and ends on it, with 50mb of "free" space left on the compressed volume to serve as browsing cache space. It was snappy as hell.
I have only done this a few times as just a lesson in self-punishment/"let's see what kind of frankenstein's monster we can build out of retro parts!" Type exercise, but the finished product is incredibly hard to kill, and keep dead. Bluescreens of death? Caught a nasty worm in the 10 seconds it was on the net? Power it off, power it back on. Good as new.
Gives a whole new meaning to "zombie workstation".
I have a celeron POS I am contemplating doing this to actually. I would prefer ramdisked win2k or better though, but I don't know of a way to boot the OS out of a block device after NTLDR starts, and before control is passed to NTOSKRNL. Maybe a hacked FreeLDR from reactos would work though.