Exceeded broadband usage

[#1]

I very rarely exceed my 10GB monthly broadband use.
Yesterday (Thurs 31st October), using my computer in the same manner as usual, i racked up additional useage at the rate of almost 1GB per hour. Alerted by the email telling me that my usage was exceeded, i called Plusnet. I am the only person in the house using Plusnet on my Apple Mac computer.
The initial agent tried to fob me off by saying that i must be downloading or updating programs or that the 13 photos i uploaded to Facebook/Flickr had caused this. The pictures are only 2.2mb each. I watched 30 seconds of youtube footage. No programs downloaded or updated. I don't do games or streaming etc. Not happy, he put me through to technical support. They took remote control of my computer and could find nothing which would cause this. In the hour and a quarter we were on the phone, my useage went from 10.63GB to 12.29GB eventually finishing the day at 12.97GB when i switched the router off.
Called Plusnet this morning and hard wired the Mac to the router. Wireless switched off. Still used 1.2GB in an hour.
Called Plusnet again and wireless password changed. Again my computer looked at by remote and nothing found.
Plusnet saying there must be something on my Mac which is doing this and might be wise to ring Apple.
Has anyone else experienced unknown data useage of this magnitude?

[#2]

Did you try to update your Mac to OSX Mavericks?

[#3]

Not updated my MAC since new in May. Is this likely to remedy the problem? Thanks

[#4]

No, I am just wondering if your Mac updated to the new OSX because it is a large file (around 3.9 GB).
If you click on the Apple logo on the top left and go to "About This Mac", which version are you running now?

[#5]

OSX 10.8.5 (12F45)

[#6]

When the Plusnet assistant took control of my computer, they looked at everything it had done over the last two days. No programs downloaded or updated. They also looked at all the web pages i had accessed and my emails. Nothing any different from any other day. They seem to be pinning it on my Mac doing something of its own accord, but they couldn't identify anything, or that my wireless had been hacked and someone outside was using it to download. Hence, password changed to see if this solves the problem. Am using an old windows laptop at the moment to see how useage goes. If all seems to be normal they have asked me to record this, then reconnect the Mac to see if it is the probelm. Ta

[#7]

I would imagine it is your mac trying to update things.
You're running the latest version of OSX Lion.
It might be worth having a look at this http://reviews.cnet.com/8301-13727_7-57580828-263/use-nettop-command-to-check-per-application-networ... It tells you how to monitor your network activity of all applications/processes on your mac (just in case something is using traffic when it shouldn't).

[#8]

he's not running the latest version of OSX Lion.
10.8.5 is Mountain Lion.
and Mountain Lion doesn't auto update anything without you allowing it to.
it will tell you there are updates available, but it doesn't go and download the updates on its own.

[#9]

See the Software Update Preferences section on this page:
http://support.apple.com/kb/ht1338
You may be set to 'Download newly available updates in the background' ?

[#10]

This could be unrelated but I was also told I had exceeded my limit.  I only use the internet for emails and ebay, no downloads, no photos NOTHING.
It was also found to be active when I was at work.............. so I turned it all off after every time I used it seemed to solve the problem, but I then decided to go unlimited.

[#11]

Thanks for your helpful replies. However, as stated previously, the Plusnet assistant having taken control of my computer examined all its activities and whether any downloads had taken place or updates. They also looked at whether it was set to auto download, which it isn't. Absolutely nothing was found. Still using an old windows machine at the moment. Switching the MAC on tonight after midnight to see what happens.

[#12]

It might be worth changing your wireless password as well in case someone "nearby" has hijacked your connection and is using your bandwidth.
If you are using WEP then it can be hacked in minutes, WPA2 is slightly more secure

[#13]

Hi Geoff,
The exact same thing has happened to us on the exact same day, usually we will use only half to three quarters of our 10gb down load then on the 1st of November on Friday we somehow have downloaded all most 6gb, in one day. I was suppriesed because I was away from the house from Wednesday till yesterday (Saturday). The only thing that is different is a red light has appeared on the router next to the internet symbol this means we are not connected to the internet but we still have it????? Anyway I will be ringing plusnet on Monday and asking why they did not just put us on the unlimited which cost only two quid more like they said they would rather than charge us 1 pound per GB. We are now up to 17gb this month with over two weeks left. Have been with plusnet for over three years renewal due in January, it may be a change of supplier.

[#14]

Looks like after a password change, things have returned to normal. However, Plusnet tell me that as they cannot see a problem their end, it must be at mine. However having taken control of my computer and looked at it's activities, they cannot find a problem at my end. However they insist that the additional 15GB used, must be at my expense. This puts me on 25GB with almost two weeks left to the end of the month.
Not happy with Plusnets treatment of this situation. But what can you do. It's shocking to hear someone else has also experienced the same problem. The initial response from Plusnet was deplorable. The engineers have cleared Plusnet of any blame and myself. Can only assume i was hacked. Most other firms would treat this with a different attitude. Although i have always praised Plusnet....things have just changed.

[#15]

Unfortunately all Plusnet can do is check the equipment you're using and possibly see if any rogue users are on the router at they time they investigate - the chances are it cost them far more in staff time than it did in data costs.
It would be worth keeping an eye on your data usage on a daily basis for the next couple of months to make sure that whoever may have been using your connection (if this was the case) hasn't found another way in.
Fingers crossed it is all sorted for you.