Question: I have this small virtual server (1GB RAM, 1 vcore), which served me well untill it suddenly started reporting 100% CPU usage because of kswapd0.
Memory consumption is between 50% and 60%.
I've set swappiness to 0 just to check if it releases CPU resources, but it did not.
I've had this issue on 16.04, and now on 18.04 after upgrade.
How to get rid of this kswapd0 CPU hog?

Answer: 
In case someone faces the same issues - the reason was malware: `Multios.Coinminer.Miner`.

`kswapd0` was a binary file located in `/root/.configrc/a/kswapd0`.
What you need to do is:

1. Clear crontab jobs referring to `/root/.configrc`
2. Clear `ssh` keys
3. Delete `/root/.configrc`
This is also relevant for 20.04. I caught from a Steam user adding content to the KillingFloor2 Dedicated server. Here's what it looks like.

Results of `crontab -e`:

[![crontab -e](https://i.stack.imgur.com/3mB3d.png)](https://i.stack.imgur.com/3mB3d.png)

Results of `htop`:

[![htop](https://i.stack.imgur.com/KGhBb.png)](https://i.stack.imgur.com/KGhBb.png)

**How to solve this problem:**

1. I commented lines in the cronjob
2. Rebooted the server (CPU calmed down)
3. Deleted the .configrc folder
4. Checked again the paths of the crown and cleared it.