What is PasswordBreachAgent and why is it running in the background on my Mac?

My best guess is that this process is probably checking the passwords in your keychain for whether they're known to have been breached (by submitting hashes of them to an online service like "Have I been pwned?" and comparing to hashes of known breached passwords). This is also mentioned as a new feature here in the Safari section:

https://www.apple.com/macos/big-sur/features/

I have also found this process on two installations, one clean, one not. The process itself doesn't seem contain much, mostly references to Apple root certificates. It's probably a new feature of Safari to advise the user in case of weak or leaked passwords or something like that. Anyway, a malicious process would disguise itself with a much better name than PasswordBreachAgent

PS

Didn't see the posts above, it all makes sense now

sshg123 wrote:

Hi Guys,

I just did a clean install of Big Sur on my MacBook Pro 15 Late 2013. When I opened activity monitor, I found a process called PasswordBreachAgent running. Anyone know what this is? It is stored at /Library/Apple/System/Library/CoreServices/SafariSupport.bundle/Contents/MacOS/PasswordBreachAgent

Any info would be helpful. It's a very ominous name for a process - but as it stands the only software I have installed so far from a more obscure developer is a ad blocking app from the App Store called Wipr. Other than this, this is a clean fresh machine.

It's really strange that there are almost ZERO google results on this. I would think that the name of the process would get more people a little concerned.

Any input would help. Thanks.

If you are not having any problems I see this as a non-issue.

It is a legitimate process as you document, from the Finder>Go>Go To Folder:

/Library/Apple/System/Library/CoreServices/SafariSupport.bundle/Contents/MacOS/PasswordBreachAgent

ref: macOS - Security - Apple https://www.apple.com/macos/security/

ref: Apple Platform Security - Apple https://support.apple.com/guide/security/welcome/web

About the read-only system volume in macOS Catalina /Big Sur- Apple ...

sshg123 wrote:

It's really strange that there are almost ZERO google results on this. I would think that the name of the process would get more people a little concerned.

I've heard a rumour that Apple is working on its own search engine. I think that would be a welcome development. Google has become a source of conspiracies and fake news. I'm not surprised you wouldn't find anything about this on Google.

However, if you just check your Mac using the "man" command, it explains exactly what this app does:

And for the record, this works via hashes. Your passwords are not sent anywhere. There are websites that will do this (such as https://haveibeenpwned.com) but they are little more than ads for 3rd party security software that duplicates functionality that is built into macOS. And if Apple is doing this check, you can be certain it will be safer than entering your password on some random internet site.

It's really strange that there are almost ZERO google results on this.

Not strange at all. Unless a website has something to sell you it will be very difficult to find using Google's search engine—a product specifically designed to sell you.