Mac desktop performance is unusually slow

I don’t see anything in that report that proves someone is spying on you.

What stands out more is the 8 GB of RAM with about 6 GB of swap being used. That can make an Intel iMac with a Fusion Drive feel very slow even when there’s plenty of free storage. I’d restart the Mac first, then check Activity Monitor > Memory and watch the Memory Pressure graph while you use the Mac normally.

Your report also shows Screen Sharing enabled. If you didn’t enable that intentionally, go to System Settings > General > Sharing and turn Screen Sharing off.

There’s also an old unsigned StandardBoost launch agent listed, but its executable is already missing. That alone doesn’t prove malware. Since the report also says you don’t have a Time Machine backup, I wouldn’t start deleting files manually yet. I’d make a current backup first.

It appears that the HDD of your Fusion Drive is failing based on the Read and Write speeds:

Write speed: 449 MB/s

Read speed: 1463 MB/s

The first thing you should do is get a backup of your boot drive with Time Machine on an external drive.

One option is to get an external SSD (I recommend you get it from OWC [MacSales.com]) and clone your boot drive to the external with Carbon Copy Cloner and boot nd run from the external SSD. You will need a Time Machine backup in order to efficiently transfer your user data, settings, etc. to the new drive with Migration Assistant.

This user tip shows how to clone: Using Carbon Copy Cloner to Make a Bootable Clone of Intel Mac.

You could also user some additional memory. An addition 8 or 16 GB should be sufficient. Again I strongly recommend you get the memory components from OWC as Mac are extremely picky on the quality of the modules and OWC tests their modules in the Mac it's going into.

Performance on an iMac 8 GB Fusion doesn’t look too too bad, though write speed is down.

I’d wonder if one of the file sync services installed here might be reducing performance, as well as simply piles of apps in 8 GB leading to lots of swap activity. This iMac isn’t well-sized for its current contents.

As for checking the hardware, the DriveDx app can report disk drive diagnostic data from the Fusion.

Instructions to try an external boot: Use an external SSD as your startup disk … - Apple Community

The “StandardBoost” stuff looks like adware, and should probably be cleaned up

If you do not have a recent local, disk-based backup, your computer is like a ticking Time bomb. You are only one disk failure, one mainboard failure, one crazy software, or one "oops" away from losing EVERYTHING! Drives do not last forever. It is not a question of IF it will fail, only WHEN it will fail.  In addition, you never know when crazy software or Pilot Error throws away far more than you intended.

If you are using another direct-to-disk backup method that you prefer, and you currently have a recent disk-based backup, that is great. If not, you should consider using Built-in Time Machine. Take steps to acquire an external drive as soon as possible. If you buy one, a drive 2 to 3 times or larger than your the amount of data to be backed up is preferable for long term trouble-free operation. Do not pay extra for a drive that is fast.  (You can get by for a while with a "found" smaller drive if necessary, but it will eventually become annoying).

Attach your external drive and use

Settings > General > Time machine ...

... to turn on Time Machine and specify what drive to store your Backups on.  It may ask to initialize the new drive, and that is as expected. APFS format is default format if running MacOS 11 Big Sur or later.

Time machine works quietly and automatically in the background, without interrupting your regular work, and only saves the incremental changes (after the first full backup). Time machine backs up your machine — including every connected drive that is in a Mac compatible format. it can not back up Windows format drives.

Time Machine's "claim to fame" is that it is the backup that gets done. It does not ruin performance of the rest of the computer while doing its backup operations. You do not have to set aside a "Special Time" when you only do backups. When you need it, your Time machine Backup is much more likely to be there and be current.

How to use Time Machine to Backup or Restore your Mac:

Back up your Mac with Time Machine - Apple Support