Router High CPU Usage

[kraM1t]

Hi, I notice after a few days my Router CPU usage is spiking to 88-99% and just sitting there constantly at that until I reboot the Router. I've tried factory resetting it but it results in the same thing after a few days. When the CPU usage is high the internet becomes very slow, not in speed but in responsiveness, eg images taking 20 seconds to load etc.

The error log is just filled page after page with this until I reset it then the logs look normal

Any idea?

[Ripshod]

How are you seeing your cpu usage? Third party router? Are you using this router to stream media or share files from a usb drive? Any parallel paths in your network?

[Cynric]

@kraM1t I'd be a bit cautious about "accept(http)" rather than "accept(https)" unless that's just LAN traffic, there isn't enough detail to say for certain.

[kraM1t]

@Ripshod It's the regular THG3000 router, CPU usage is on the Status & Support tab. No media sharing or usb drives. Just Wifi devices and 4 ethernet, it usually sits around 3%.

@Cynric Not sure what you mean, what can I upload to help diagnose?

[Cynric]

@kraM1t I couldn't tell if the logs were related to you devices (LAN = Local Area Network) or external internet connections. But @Ripshod has spotted something.

[Ripshod]

Now I can see the image it's clear your router is being flooded, either an attack or a parallel path. Does this happen with just one device connected over WiFi? 

[kraM1t]

It takes a day or three for the flooding to re appear, I doubt I could keep the family off for that long to test it lol

How would I know if I have a parallel path going?

[Cynric]

@kraM1t It could (note "could" and not "is") be that one of the devices has got a virus. With Windows there is it's own antivirus scanner which is reasonable, but you can get a good free one to double check. Don't get "Bull Guard" as it's a right pain to uninstall and it's not that good. On Android there are also free ones you can use. Indeed there's one called "Malwarebytes" that is available for both Windows and Android.

On Linux there's ClamAV which is free and Open Source.

Sorry I can't comment on Apple.

I guess that disconnecting all the devices and putting them back one at a time two or three days apart isn't going to work for you household. You may just be able to connect them or disconnect them when the router is busy and watch the router status lights to see if they change the flashing pattern or speed.

[Jayach]

I think if I saw something like that in my router logs, I would suspect malware on one of the devices.

Have you run a malware check on all the devices?

Following @Cynric's suggestion, do you have any extra routers/switches or other networking gear in use?

[kraM1t]

Okay I will try the AV scans thank you. I have a powerline switch but this issue occurred before installing that.

Thanks guys