Mayayana wrote:

Just a note about a current attack. I just got an email
with an attached .SCR. No message. Screensaver!
I'd forgotten those existed.

I changed HKCR\.scr default value to "txtfile" and deleted
HKCR\scrfile\

I don't know of any reason for screensavers to still exist.
I certainly don't use them.

An .scr is an executable file, just like an .exe file. A screensaver
file contains executable code. The only reason .scr was used as a
filetype was to allow Windows to search on that extension and presented
is a candidate screen saver program. As such, your e-mail client, if
properly configured, should have blocked the dangerous .scr attachment,
or any other executable attachment. A .scr file is a program aka
app[lication]. As I recall, MS Outlook used the registry to list which
extensions were dangerous. Other e-mail client should still have a
similar feature (integral, ini file, or registry entries) to denote
which extensions (level 1) for attachments it considers unsafe. No one
has been able to send me an .exe or .scr file for a long time, like
decades. Hell, the e-mail provider should already do the blocking (and,
if so, afford an override option).

Some users think a black (blank) screensaver consumes less power than an
all-white screensaver. They don't know how LCDs work. All all-black
screensaver consumes an itty bitty more power than an all-white
screensaver, because of the lack of having to apply power to twist the
polarizer to block the light from the LED. The backlamp is always on.
Whether you see it for a pixel depends on whether or not the polarizer
is energized. An energized polarizer consumes more power than a relaxed
polarizer.

Lots of users like to use their computers for entertainment. Many
screensavers are for entertainment. Instead of, say, playing a video
game, they want to watch a fireplace, aquarium, a light show, or flip
through a bunch of pictures (slideshow). After all, there are TONS of
tweaks to Windows that having absolutely nothing to do with using the
OS, but are for personalization (i.e., fluff). Screensavers, for those
users, would become worthless when wallpapers also become worthless.