How do I stop this?

[telsave]

When I am on the Internet every couple of searches Google buts in with a Captcha and this message

Our systems have detected unusual traffic from your computer network. This page checks to see if it's really you sending the requests, and not a robot. Why did this happen?

This page appears when Google automatically detects requests coming from your computer network which appear to be in violation of the Terms of Service. The block will expire shortly after those requests stop. In the meantime, solving the above CAPTCHA will let you continue to use our services.

This traffic may have been sent by malicious software, a browser plug-in, or a script that sends automated requests. If you share your network connection, ask your administrator for help — a different computer using the same IP address may be responsible. Learn more

Sometimes you may be asked to solve the CAPTCHA if you are using advanced terms that robots are known to use, or sending requests very quickly.

What is the best way to check that I am not suffering from malware my virus checker (AVG) is up to date and has signified nothing. I have also run the Microsoft scanner still nothing, so any ideas how I can prevent this captcha appearing every couple of searches it has just started doing this.

cheers

 

[ManofScience]

Maybe try malwarebytes, install and update it - then run a full scan in Safe Mode

 

[Exos]

Have you looked to see that you don't have any browser plugins causing it. It's amazing how many times I look at people's PC/Laptop and they have some silly spurious search bar which is installed as part of some other piece of free "ad supported" software downloaded from the net (WebPro, MayWay, Ask, Bablylon 9 etc etc)

Change your browser, see if it does the same? Something is obviously intercepting/sending traffic.

Also , try Spybot S&D, run CCleaner to make sure all your cached items are cleaned etc.

Run Glary (as an aside), to clean up your system.

 

[Spectre]

Not using a proxy are you?

Maybe a caching proxy of the ISP?

I wonder if something has changed your user agent string.

What does it show as here? whatsmyuseragent.com

Install Wireshark if you want to see what requests are being sent over your network interface. It's a little in-depth but would be interesting to see.

 

[Tamarc]

Hey Spectre,could you tell us a bit more about this "Wireshark" thingy,sounds interesting but getting fed up doing things like this and getting nowhere,or way in over my head...thanks

 

[Spectre]

Hey Spectre,could you tell us a bit more about this "Wireshark" thingy,sounds interesting but getting fed up doing things like this and getting nowhere,or way in over my head...thanks

Download it and have a go .

wireshark.org

It's a protocol analyser (sniffer) which will show you what is going through your network interface. You can watch what browsers and such send. It's a bit confusing at first when you run a capture (try running one when submitting a search to Google) until you apply filters to the captured data.

You could install the Firefox plugin Live HTTP Headers too so that you can compare their output. Wireshark would show what Google is getting from the browser or something else on the PC. I'd post a capture but I'm using SSL so you wouldn't see much interesting apart from encrypted data.

Also, on a wireless network (if you have a suitable adapter) you can watch what other people are doing . You can do things like session reconstruction where the sniffer puts the packets in order to view what was transferred.