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: 
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.
**Malware running as guest**

If you have ever enabled Ubuntu's guest account and later enabled SSH, you may have malware running using your guest account.

```
sudo find /home -f kswapd0

```

It can be found in any user's home directory, such as `/home/guest/.configrc/`

Joining any network (conference, cafe, city) that has a compromised machine, or if you use a service like `ngrok`, all while having SSH open on your system leaves your computer exposed to this simple guest vulnerability.

Because privileges were never elevated (guest can't write files outside /home/guest, nor sudo without password), I was able to delete the guest account and everything is running normally.