This was about 6-9 months ago and I didn’t lead the postmortem, so to be honest I don’t recall how we determined that.
However anecdotal, the user who was compromised is aware enough not to re-enter their credentials outside URL schemes that match our password manager database, and they wouldnt have entered anything.
“Oh but how can you trust the user, they clicked a bad link?!”... again this email came from a very reputable vendor who we email with regularly, and the link would have been completely normal for a Monday morning in Q1 2020.
I also think part of our reasoning for why the credentials were not re-used was because all the sessions seemed to be headless chrome sessions, but no logins.
I’m not a data security expert, but in my best summary, it seemed they:
- Had a “virus” that spread really well. I’m assuming they had two kinds of users. Spreaders, and targets. Our employee was a spreader, sending this bug out to his/our network. Once the targets were hit, they’d be selected out of the spreader pool (so the hackers could remain undetected).
- The hack relied upon identifying ,mutually high volume (trusted) email senders.
- The hack had something to do with leveraging the platform of Notion.io. Unsure if there is a bug on that platform which was also being abused, or if they just have a good system for hosting phishing pages.
- The user’s authenticated sessions seemed to be hijacked and replicated across the globe in headless chrome browsers, which appeared to renew the session until the hack ended.