I'm using a ThinkPad t14 notebook with Windows 11 Pro 64bits version 23H2, with Mozilla Firefox version 129.0.2.
I accessed with Mozilla to an infected site, and the Kaspersky Internet Security application don't detect it. More over: I run a full scan, and it report 1 file uninfected and quarantined, but trying yo identify the file, the Quarantine entry for the Kasperksy menu does not show any file.
Nevertheless, starting Mozilla immediately appears a message from the virus (see the attached file). The virus message content changes every time I access Mozilla, but it has every time the same structure.
I refreshed Mozilla and the virus apparently disappear.
Is it safe continuing using Mozilla? Do I need to make a deep clean of my notebook?