3 posts tagged “passkeys”
2025
A Sneaky Phish Just Grabbed my Mailchimp Mailing List (via) In further evidence that phishing attacks can catch out the most sophisticated among us, security researcher (and operator of ';--have i been pwned?) Troy Hunt reports on how he fell for an extremely well crafted phishing attack against his MailChimp account which then exported his full list of subscribers, including people who had unsubscribed (data which MailChimp stores and continues to make available).
This could happen to any of us:
I've received a gazillion similar phishes before that I've identified early, so what was different about this one? Tiredness, was a major factor. I wasn't alert enough, and I didn't properly think through what I was doing.
Troy's account was protected by authenticator app 2FA, but the phishing site (on the realistic sounding mailchimp-sso.com domain) asked for that code too and instantly proxied it through to MailChimp - somewhat ironic as Troy had been promoting phishing-resistant passkeys on his trip to London, a technology that MailChimp doesn't offer yet.
There are a bunch of interesting details here. I appreciated this point about how short-lived authentication sessions can reduce account security by conditioning users to expect constant login requests:
I also realised another factor that pre-conditioned me to enter credentials into what I thought was Mailchimp is their very short-lived authentication sessions. Every time I go back to the site, I need to re-authenticate and whilst the blame still clearly lies with me, I'm used to logging back in on every visit. Keeping a trusted device auth'd for a longer period would likely have raised a flag on my return to the site if I wasn't still logged in.
It looks like MailChimp preserve the email addresses of unsubscribed users to prevent them from being re-subscribed by future list imports. Troy discusses this issue at length in further updates to the post.
Also interesting: this article by DNS forensics company Validin which tracks down the responsible group using DNS records and other hints such as title tags and favicon hashes.
2024
The problem with passkeys is that they're essentially a halfway house to a password manager, but tied to a specific platform in ways that aren't obvious to a user at all, and liable to easily leave them unable to access of their accounts. [...]
Chrome on Windows stores your passkeys in Windows Hello, so if you sign up for a service on Windows, and you then want to access it on iPhone, you're going to be stuck (unless you're so forward thinking as to add a second passkey, somehow, from the iPhone will on the Windows computer!). The passkey lives on the wrong device, if you're away from the computer and want to login, and it's not at all obvious to most users how they might fix that.
[Passkeys are] something truly unique, because baked into their design is the requirement that they be unphishable. And the only way you can have something that’s completely resistant to phishing is to make it impossible for a person to provide that data to someone else (via copying and pasting, uploading, etc.). That you can’t export a passkey in a way that another tool or system can import and use it is a feature, not a bug or design flaw. And it’s a critical feature, if we’re going to put an end to security threats associated with phishing and data breaches.