wifi interuptus

have been forced to use wifi due to router failure and i noticed the lights on my router blinking as if i were down loading and my questions are this .....without dealing with the router, i know sod all about routers, and any way to confirm a hack in the wifi system ....i am wep password protected ......where i live im pretty sure it would be a smart phone, if im being used and if a computer it would surely be a windows...and is there a way to get an ip address if i discover an intrusion ......i have used surplus meter and it was actively indicating a download i wasnt doing .......is there dialogue the back ground that could cause this?.........i gave the lady below me permission to piggy back to check her whatsup app but the surplus meter was active when she wasnt on the system thanks
hope you all are well
d.

Here's a bit of advice for you: If you are "WEP" password protected, you really are not protected at all. Nowadays, you should be using the strongest possible encryption available. You don't mention what Mac you have or the router, but WEP is a very old method of encryption which is no longer recommended or supported by Apple. Update your equipment.

Agreed. WEP was insecure and completely hackable ten years ago. It has only gotten easier and faster to break into it in the last 3,650+ days.

WPA2 Personal is currently the best consumer-level encryption that's available that's also widely supported and easy to use. It, too, can be broken, but it is definitely better.

I would encourage you to, at a minimum, CHANGE your encryption passphrase and see if the behavior changes that you're describing. Best-case would be to move over the WPA2, apply MAC address filtering, and move on from there.

Use WPA2 as has been discussed. But the blinking lights may not be a download. The network is constantly sending and receiving acknowledgement packets from all connected devices and with the upstream net at your ISP. So the lights blink all the time whenever anything is connected.

That said, you can check who's in your network by logging into the router control screens (You'll have to find out how to do that for your router), and look at what's logged in. There is an app for the iPhone called Fing that also will survey the wifi network and tell you what is currently in the same network as the iPhone, so you could use that to see if anything strange is there.