Suspicious Autofill on Chrome

Question

I was looking at signing up for an online account at a reputable web site (Vanguard) when I noticed something suspicious. When the site prompted me with a form to enter my name, I noticed--as usual--multiple variations of my name with previous addresses that I've had from Chrome autofill. But in addition to this I noticed the name of a friend I knew in college years ago. It included his first and last name with the zip code he currently lives in. This person has never had physical access to this computer, and I am signed in using a recently created google account that he has no knowledge of. Most interesting is that the autofill includes his current zip code that wasn't associated to him when we were in the same city.

Has my computer been compromised? What has happened here? While this is the first time that I've tried to sign up to this site, I've never seen his name show up in autofill applications before. Can I trust any of my accounts going forward?

Answer 1

It's very unlikely to indicate any security breach; I can't think of any attack that would involve or result in adding content to browser autofill. It would be unusual for someone to fill in their real name in that scenario as well.

As for how it could have happened, here's what I'd suspect. Autofill remembers, for a given field name, everything you type into that field. It can unintentionally have separate entries "FirstName" and "First name", depending on how the fields were called in the page's code. They're not split by purpose, on the other hand, so if you enter someone's name in a people search form, autofill could later suggest it as yours.

Using a different google account won't necessarily reset autofill, as the data is stored on the local PC. Browser data can even travel between two PCs via a common accounts, then between accounts on the new PC, so one can occasionally dredge up really old pieces.