Firmware update available for UEFI dbx from Unknown App

A message popped up from an 'Unknown App' advising of a firmware update available for the UEFI dbx today.

It is possible to issue the command:

sudo fwupdmgr update

After entering the sudo password, a list of firmware-updatable devices in the machine are listed along with any available updates to their firmware version.

The Upgrade UEFI dbx from 20240301 to 20241101 output is shown below with the option to Perform operation? [Y|n]:

Upgrade UEFI dbx from 20240301 to 20241101?
╠═══════════════════════════════════════════════════════════════╣
║ This updates the list of forbidden signatures (the "dbx") to the latest
║ release from Microsoft.
║
║ An insecure version of Howyar's SysReturn software was added, due to a
║ security vulnerability that allowed an attacker to bypass UEFI Secure Boot.
║
╚════════════════════════════════════════════════════════════════

Say Y

Perform operation? [Y|n]: Y
Waiting… [***]
Successfully installed firmware
An update requires a reboot to complete. Restart now? [y|N]:

See also https://www.welivesecurity.com/en/eset-research/under-cloak-uefi-secure-boot-introducing-cve-2024-7344/