Help with self perpetuating suspect folders

Viruses and worms
1

So, I’m a resonably savvy user with no outstanding skills computer wise. Today I noticed weird folders with weird content not of my making. Deleting them makes them go away for a while until they reappear with similar names, although not identical. No other obvious symptoms as yet. There seems to be at least one on root level of all fixed drives.

Avast does not say anything. Spybot S&D doesn’t indicate anything. CyberReason Ransomfree is happy. Win 7. MS Office 365. Various non exotic freeware from reputable sources. Do surf a lot but keep to mainstream page content. No stolen software.

Anyone have any idea about the manner and level of crap I’ve managed to contract and what to do about it?

Example names of folders:
C:
ALcached125
Xuse89

Sample content of folders:

C:\Xuse89>dir

Innehåll i katalogen C:\Xuse89

2017-06-20 00:13 .
2017-06-20 00:13 …
2017-06-20 00:13 513 849 crowdvague.xlsx
2017-06-20 00:13 256 671 do4L.docx
2017-06-20 00:13 52 598 excitement ignored least.pem
2017-06-20 00:13 64 913 gentleman_carolina_transformation.xls
2017-06-20 00:13 99 516 independent_needle_sovereign_charges.rtf
2017-06-20 00:13 417 318 kxhsvSqUjmnc.doc
2017-06-20 00:13 18 493 loverprimarilyrecreationmight.sql
2017-06-20 00:13 276 940 paris.voters.movement.jpg
2017-06-20 00:13 202 025 percentshownsharedjail.mdb
2017-06-20 00:13 13 843 stairs.quart.granted.clothes.txt

2
CyberReason Ransomfree is happy...........
Did you read the instructions? ..... I guess not, and you are not the first one

Strange folders and files appeared on my disk >> https://rejzor.wordpress.com/2017/01/20/strange-folders-and-files-appeared-on-my-disk/

3
Spybot S&D doesn't indicate anything
I recomend replacing this with Malwarebytes free
4

Nope - did not. Read up on a few reviews and installed what I deemed were decent and relatively self sufficent tools (which is how following a recent reinstall came back to Avast after a period of infidelity).

Rarely am I so happy to be the idiot as when someone tells me I don’t have a problem.

Will replace my trusty old Spybot as per your recommendation too.

Many thanks!