This is a general enquiry and an admission of a follish error, but I expect I am not the only person this has happened to.
First of all, I should say my computer is behaving perfectly normally except in one small respect. I am running Windows 10, using Windows Defender as my virus and firewall software, and occassionally running Malwarebytes to check for malware.
However, at the weekend I was using iTunes to update my iPhone SE which was too full to update wirelessly. The update failed and my phone was stuck at the recovery screen and so I called Apple support. To cut a long story short they asked me to do several things, including switching Windpws Defender off at one point, and a little later asking me to update Windows 10. It is since the update that I have been getting problems with my screen - the background flashes off for a fraction of a second, sometimes repeatedly, but not enough to cause me any real problems.
The major problem, and the reason for this post, is...you guessed it....I forgot to switch Windows Defender back on. Only realised it was still off this morning, so I have had no protection from Saturday afternoon to Thurs morning.
I ran a scan as soon as I realised what I had done, and downloaded and ran the latest version of Malwarebytes. Both found no threats, but I don't know a lot about how virus and malware work. I did some online shopping during those 5 days using both debit card and Paypal and I'm worried that these details, or my passwords (some kept in Keepass, some stored by Google Chrome) may have been stolen while I was unprotected.
Could this happen without leaving a 'threat' behind that could be picked up by my anti-virus software? Could a virus cause my anti-virus software to malfunction so that it doesn't detect threats properly?
Have I just been lucky not to have picked anything up during those 5 days, or is there anything else I should be doing to protect myself?