I think my home network was hacked :(

So today I got an alert from my cable provider saying we’ve almost hit our bandwidth limit. I didn’t even know we had a limit. We do and it’s a terabyte a month. We’ve never come close before.

Here is a chart:

So in May my son came home from college with his PC and laptop. I asked if he has been doing any big downloads, etc, but we calculated the games he’s downloaded and while it seems like a lot (100GB in the last few days), it’s not anywhere near a terabyte.


So maybe someone a little more Internet savvy can tell me what can use a terabyte a month in bandwidth? To me, it seems like something nefarious, like someone is using one of the PCs in the house for bittorrent seed or something? I have no idea.

  1. How can I check?
  2. Is there something I can download to show me which of the computers in the house is the guilty PC?
  3. I have Win 10 PCs, an iMac, and a few laptops. Is this the sort of thing where I have to scan each of them to see if they are clear?

I’d appreciate your thoughts on how to proceed.

Streaming 4K will burn ~25GB an hour.

Hey, thanks man. I’m sorry, but what streams 4k? Does my Roku stream 4k? If I’m watching Deadwood on my PC, is it coming to me in 4k? Or is that something I would have to request, like checking an option to only stream in 4k?

Sorry. Netflix will stream 4K, perhaps other services too. You have to request it as it’s a higher tier plan.

Some game wikis play multiple streams from a streaming service they advertise. Chrome doesn’t do a good job of stopping the streams in background tabs etc. I lost 120 gb or so to this. Might be something to check.

“bandwidth limit”… disgusting!
I remember that from when I lived in a small town in Germany. It was really easy to get over the limits by accident.

See if you can turn on logging in your router.

Address will be or almost certainly.

Is your son honest? Friend’s junior high school age kid was doing TB worth a month of TV and movies via newsgroups. Despite denying it.

Have you tried the Safety Scanner?
(Unfortunately needs to be downloaded and run on each machine)

Seems your son is by far the most likely vector, whether downloading or streaming (I think Twitch/Youtube goes up to 4K these days, but even if not, it all adds up). Why not just look in your router and see what devices are using up bandwidth?

If your router has a firmware update, update it, reset to factory settings, set up a new password for your router and WiFi network. Tons of security updates for lots of routers lately.

If you still have problems, then your son is sucking bandwidth, either through malware or streaming or torrenting.

Thanks for the ideas guys.

It sounds like it’s probably just a lot of gaming/videos, and nothing nefarious. It just seemed like a lot of traffic, but it’s probably just heavy use.

I updated the router firmware. I can see which devices are attached over the wireless and they are all known clients. I will just keep an eye on it. I don’t see any options for tracking by client, but that would be a handy feature.

This was the most likely explanation that came to me after reading the OP. Under-30s have no idea how much bandwidth they chew up just doing their usual stuff. We struggled with data caps (and expensive “additional gigabyte charges”) on our phones for a long time until we started using a per-phone cap instead of a pooled data plan. The boys started noticing once there were individualized consequences.

Your router can most likely show you what devices are connected to your network.

One thing you can do, is enable something like MAC address blocking, so that only devices you specifically allow on your network can get on. It’s kind of a pain if you are connecting lots of devices all the time, but otherwise it’s not that big a hassle, and makes it a bit harder for someone to hop on your network.

It seems like this is most likely your son though, given the huge burst came about right when he showed up.


Well, at least we know it’s not me. :)

We had the same problem on the phone data plan and worked it out by just asking everyone to be careful and explaining how to get on a nearby wifi, if one is available. I didn’t even realize we had a cap on the cable plan. Hopefully now that we know it’s a thing, we won’t go over the threshold.

Thanks everybody for your thoughtful ideas and suggestions. I’ll report back if I find something interesting.

Almost all ISP plans have a cap, and it’s usually 1TB. That said, even with 4K streaming and a bunch of game downloads, I never come close. You should definitely change the password on your home network and check your router to see if you have any unknown machines on your local network.

I also have Comcast and shared the password with a neighbor. Their computer got malware and started chewing through data. When that happened, I got an automated call from Comcast telling me to check my devices for malware. (I changed the WiFi password, hoped they wouldn’t ask for the new one, and that was the end of it.) So, if you didn’t get that call, I think that’s an additional re-assurance that it’s legitimate traffic.

Sounds like you may have a handle on your problem, but I’ll link my old (similar) topic just in case -

In my case, looks like I was actually hacked and someone used my network to torrent some random pirated show. On the upside, after I did some updates and changed passwords and such, it hasn’t happened again. Yet, anyway.

If your son games/watches videos as much as mine, it’s almost for sure him. When we had a 1TB limit he’d download a few games to his XBOX and also would be watching Netflix on the XBOX (streaming at 4K as the XBOX can do that, and he has a 4K display on it) while playing MTG Arena on the PC.

This all going on while I’m also downloading, viewing, and gaming just like normal, of course. We hit 700GB every month, and often had to slow down/curb our use as we got close to the end of the months, in the summer time. I’m at a 4TB limit tier now so it’s not an issue any more, but what you are describing is exactly what I have experienced. XBOX games are also freaking massive, too. One game he pulled down was 120GB and that was not much higher than what most of those games take up (and sometimes he would need to re-pull down several games as multiple friends wanted to play a specific game with him).

So far, I haven’t seen anything from Comcast about tiers and data caps. I’m never sure why though. We live in a small town, and for the most part, Comcast is our only option and I’m surprised they haven’t put the screws to us yet.