Malware/adware on Chrome? Extension found that I did not install
Hi everyone,
Macbook Pro running Yosemite 10.10.5, retina, early 2013 model
Processor speed 3Ghz
8GB memory
Chrome 45.0.2454.85
Context: I did a format/erase and clean OS X install on my Macbook 1 day ago and only restored music/pictures from a Time Machine backup, not any of the profiles, settings or applications as I definitely had some sort of malware/trojan/adware (login on a social networking site from a country I have not set foot in) on it and it would've most likely been lurking in one of those folders (this I was recommended by someone else).
Anyway, I left my Macbook on overnight as I was downloading some podcasts from the iTunes store. When I woke up today to check my email etc, I noticed an extension installed in Chrome that I definitely did not install and something that was not on Chrome the night before when I was actually installing extensions - "Google Docs Offline". I know I didn't install it because I don't use Google Docs and as far as I know, there is no separate extension for for using Docs offline. When I clicked on details, it showed up in the Chrome web store, with about three million users and I think only four ratings. It said it was provided by "Google" (not google.com or any sort of variation like that), and, only realising after how suspicious it looks, its logo was the Google Drive logo. Before I did the reinstall, I had never seen such an extension in my list before anytime I used Chrome day in, day out.
Not thinking too much of it, I trashed it and didn't jot down any specific details (e.g. Chrome web store web link, or a screenshot of it). However, I tried searching for it in the web store by myself and I cannot find it. So now I'm worried that I have malware on my computer.
I haven't noticed anything obviously suspicious with my Chrome activity - I don't have redirects or pop ups and there were no other extensions in my extensions list that I didn't install myself. However, I did have a couple of ERR_CONNECTION CLOSED messages and other similar ones last night. However, this might be chalked up to the fact that my house had a new router installed.
I did some scans; neither Avast or MalwareBytes for Mac found anything.
Now I'm not entirely sure what to do!
MacBook Pro with Retina display, OS X Yosemite (10.10.5)