I-Firefox Isithangami Sokwesekwa

I've noticed that when logging into various websites, a random email address not known to me appears in autofill among my usual email addresses. This unfamiliar address is under the @shanreto.com domain and shows up across different websites. My Firefox account is synced between my PC and mobile phone. Both devices are password-protected and under my control at all times, and I have only installed uBlock Origin as an extension.

Could there be any explanation other than the possibility of someone accessing one of my devices through malicious software or similar means?

Steps for reproduce:

• Turn ON PC
• Launch Audacious player
• Launch Firefox
• Visit to drupal.org

And I have sound glitches like on radio tuning. From all software, that have sounds: players, browser, messengers. Glitches disappear after restart. I find only 2 sites, that make it: drupal.org and my local bank. With Chrome - no problems.

Without Audacious glitches can be to, but not in 100% of cases.

OS: KDE Neon Plasma 6

I have scoured the web and read/tried everything. I cannot remove the time and date stamp from my documents. No matter what program/app they are printed from it shows up ruining my printing. I've tried unchecking the header/footer box. There's nothing in my brother printer set up regarding the date/time stamp. It has to be firefox. How do I fix this? I'm not a computer guru so I need details. I'm at my whits end! Thanks!