Are these pop-up windows caused by a bug or a virus?

The strange pop-up windows may be related to the recent macOS 26.6.2 update rather than a virus.

The message saying “sharingd wants to use the ‘login’ keychain” means that a macOS service is requesting access to securely stored information on your Mac.

Why have the pop-ups started appearing now?

The timing of the update is an important clue. After a system update, previously trusted software may need to be authorised again. Another possibility is that the login keychain has become locked or that its password no longer matches your current Mac login password.

Apple explains this situation in its guide: If a Mac app you've already trusted asks for keychain access.

Does this mean the Mac has a virus?

Not necessarily. A keychain access prompt is not, by itself, evidence of malware.

macOS includes several built-in security protections, including application security controls, permissions and a signed, read-only system volume. These help protect essential operating system files from unauthorised changes.

However, Macs are not immune to malware. Malicious downloads, adware and deceptive applications can still pose a risk. If a prompt appears unexpectedly, it is sensible to verify the request rather than automatically approving it.

For more information, see Apple's documentation:

• Apple Platform Security
• About the signed system volume

What should you try first?

1. Restart your Mac and check whether the pop-ups return.
2. If they do, open Keychain Access through Spotlight search and check whether your login keychain is unlocked.
3. If prompted for a password, try your Mac login password. If you recently changed it, your keychain might still require your previous password.
4. Don't automatically approve every prompt. If you are unsure whether a request is legitimate, choose Deny or cancel temporarily. Avoid selecting “Always Allow” until you understand the request.
5. Check whether another macOS update is available. If the prompts persist, consider contacting Apple Support. Avoid resetting or deleting your keychain as an initial troubleshooting step, since this could remove saved credentials.

If you suspect a password mismatch, Apple's guide to updating your keychain password may also help.

My overall assessment

The timing makes a connection with the recent update plausible, but there isn't enough information to conclude that the pop-ups are a software bug or a sign of malware.

They are background processes (daemons)which need access to your passwords to work.

For example, sharingd is part of Airdrop and other sharing functions. I think assistantd is part of Siri. You can Google them if you want more information.