Massive broadband usage 400Gb/mth

[#1]

Plusnet are currntly showing my broadband usage at 400GB and still not end of monitoring period. 200gb is reported as other and one day was reported at 38GB. We are not a gaming family and streaming is not that much at all. Similar levels over past few months. I would expect usage to be in region of 50gb/mth.
When i spoke to Plusnet while ago said not to worry as on unlimited but starting to get concerned.
Phoned Plusnet on Monday and although helpful not resolved and sre due to call me tonight. I have done no streaming or gaming this week and kept usage to a minmum but still high usage. Have turned off devices in rotation and been monitoring logs and attached devices but still can not find what is causing it. Am rather concerned and wondered if anyone could suggest what to try next
Many thanks

[#2]

Although not ideal, if you were to completely disconnect your router for 24 hours, we'd be able to check if any data was being recorded when no connection is there.

Looking at a breakdown of download/upload, there has been a lot of uploading as well, usually between 10am to 2pm, if this helps you narrow it down at all. Maybe an automated backup or something along those lines?

[#3]

Lots of upload as well as download and overnight, sounds like could be file sharing or bit torrent as these programmes rely on the client sharing the file back with other internet users. You haven't got any teenage kids who could be downloading films / music via file Peer to Peer file sharing / bit-torrent websites via a PC / laptop left on overnight have you?

Other possibility could be a PC with a virus infection that is acting as a Spambot sending lots of emails out onto the internet. If you have any PCs check that the Anti Virus is up to date and that do a full virus scan on them for piece of mind.

Finally is your WiFi password protected and encrypted, if not it could be someone nearby piggy backing onto your WiFi signal?

[#4]

If you are using Windows 10 it may be uploading updates to other W10 PCs!

Have a look at Start->Settings->Update & Security->Windows Update->Advanced Options->Choose How Updates Are Delivered

As you can see above I have it set so updates only go to machines on my own network.

[#5]

I have just found this too over the last few days.

First while recommended to permanently leave the router on mine is on the same power as my computer so gets turned off when not in use. I have tried leaving it on but since running teats did not show any increase in my recorded download / connection speed I reverted to turning it off.

I can use 5+ GB and very occasionally ( e.g. around Christmas holiday ) 10GB a day with streaming and major computer updates but my typical usage is under 2GB a day and 50GB per month. I am just 8 days into the current billing period and the recorded usage is over 43GB including one day of over 16GB, over 10GB for yesterday and nearly 10GB for last Sunday. At this rate by the end of the month my usage could easily exceed 200GB.

My first thought is I had been hacked.

I do have Powerline adapters ( LAN over house mains wiring ) to link my router to my Youview box although I actually rarely use iPlayer etc. I have separated and re-paired these so theoretically the coding has been changed but for now I have removed them from the mains sockets.

I have also logged into my router and looked at both the connected devices and the number of Bytes downloaded and uploaded. 

Whenever I look the connected devices just show the computer am using and the allocated local I.P. address 192.168.1.x

The Bytes shown as downloaded and uploaded are in line with my typical usage.

If another device had been connected, and this would be for a while since at typically 5Mb/s maximum speed 10 + GB would take several hours to download / view, even if not somehow not showing as a connected device with a local I.P.  I presume the Bytes shown as downloaded and uploaded include all traffic for the router uptime period.

The effect is as if another router is connected to my line.

Hence I am puzzled. Before probing deeper I need to be sure there is not a Plusnet system glitch or an issue with BTOpenReach.

Has anyone else found this has just started happening?

Ultimately while the package is unlimited I know there is fair usage policy but not the details. I do not want to find my broadband is suddenly disconnected for excessive usage either overall or for excessive streaming. Also my contract is due for renewal next month and I do not want to not be offered a deal based on this months recorded usage.

[#6]

Ultimately while the package is unlimited I know there is fair usage policy

There isn't

[#7]

Hello 

After weeks of narrowing down by switching off devices and switching on one at a time i found the issue to be with my wifes hotmail/outlook account - as soon as she logged into her Microsoft account we could see the data usage ticking away  at 10 mb every 10 seconds and as soon as she logged off it stopped.

we deleted her microsoft account and set a new one up with a gmail account and all is fine. 

We were using between 300gb and 430gb a month since last November - when somehow her hotmail account got replaced with outlook - but as we are unlimited we had not noticed until recently. - am now back to around 2 to 5 gb a day. Miicrosoft have denied it is anything to do with them but I have no doubt it is the outlook - I tested it loads and spend hours and hours getting to the bottom of it

Regards .. Mark

[#8]

' Thank you ' for the responses.

First it is very helpful to know that even if the usage recorded by Plusnet on my account reaches 15GB / day or close to 500GB per month Plusnet are not going to take action to disconnect my router /  broadband service.

While Outlook / Hotmail is not my issue something similar certainly could be. I use Yahoo Mail which when you sign out loads their home page. This increasingly has more content and many of the linked pages are video. It is so easy to unintentionally  leave a page open continually loading video clips. Youtube by default similarly loads another clip when one ends. For one day this is what I presumed had happened but since then I have been very careful that pages are closed.

I have now installed a network traffic monitor application on my laptop so I can compare the records from this as well as my router to the usage recorded by Plusnet.