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I will be moving a new location in a short time, which means all of my devices will be coming with me.

My landlord is the kind of older person who needs help connecting to WiFi. Despite this, she manages to use a number of devices which connect to the internet: TV, phone, Kindle, computer, tablet... When I recently talked to her, it became evident that she did not understand the risks of clicking links in her many questionable emails. Naturally, she's happy to put me in charge of making sure everything works (but that's another discussion...).

In the interest of my own devices, what general first steps are advisable to take to secure this unfamiliar network, which could have any number of undetected threats? I'm planning on changing passwords, installing antivirus, and probably subscribing to a VPN service, but I'd like to specifically take measures to

  1. Determine (as best as possible) that nothing malicious is already residing on the network.
  2. Reduce the risk that actions taken by my landlord lead to other devices the network being infected.
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    If I were you I'd first install an access point of my own to her network, with a firewall between my gear and her network; next I'd configure all my devices to use my access point, not hers. There's no way I'd want her greasy traffic on my LAN. – John Deters Dec 8 '16 at 20:25
  • @JohnDeters That sounds like the way to go... I'm thinking that I'll do that as well as manage her router. – ZX9 Dec 9 '16 at 14:45
  • Why the downvote? I get that it's a little open-ended, but it's relevant by my interpretation of the help center and it's definitely relevant to others... – ZX9 Dec 10 '16 at 18:12
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Sounds like you should simply assume that your local network is compromised - rather like using a public library.

You might offer to help manage her router so that you can change default passwords and add monitoring for things opening unexpected ports. You can also add some outbound firewall rules and turn off UPnP if possible.

Monitoring activity through the firewall for a while and periodically thereafter will soon give you a good idea as to whether anything nefarious is happening somewhere on the LAN.

A VPN is a good idea (assuming you can live with the overheads it brings), at least to start, you might also set up a VM with direct connection to the LAN to see if anything unexpected tries to connect to it.


UPDATE: How to monitor for open ports.

This rather depends on the router model. Most will have built-in dashboards that will show you open ports and connections so that you can view them manually. Some will have SNMP available that you can connect to an SNMP monitor tool that you would run on your VM.

Or you can run something like PortScan. Or if you want to really get technical, try nmap. You would run these on your VM. There are a great many similar tools, just search for alternatives if those don't suit.

To check the generally open ports on the WAN side of the router, you can use a tool. e.g. http://www.yougetsignal.com/tools/open-ports/ or http://www.canyouseeme.org/ though these may not spot ports that are only opened to specific remote end-points. Not to worry though because your LAN scan will find all the traffic.

As for what might constitute an unexpected connection. That is rather hard to predict. But an SMTP (email) connection to a PC on the local network might be suspect, non-standard ports being opened to remote end points, that kind of thing.

  • How would you suggest I create that VM and monitor (unexpected) connections? – ZX9 Dec 9 '16 at 14:45
  • I've added an update. – Julian Knight Dec 9 '16 at 15:18

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