There have also been reports of Google Drive struggling at the same time, although it's not certain the two are related. Drive was up and running as we wrote this.

It's not certain who's behind the phishing attempt, or just what the fake Google Docs app is doing. We've reached out to Google for more. However, the company already says it's investigating the scam. The one thing that's for certain is the sheer scale and effectiveness of the attack. Both the email and the web pages look very legitimate, so it's all too easy for even seasoned internet users to fall prey to the attack. It could be a while before we know the full extent of the damage.

Update: Google tells Engadget that it has taken down the responsible accounts, pulled fake pages and delivered relevant Safe Browsing updates. Also, it's taking steps to prevent a repeat of this incident. You can read its full statement below.

"We have taken action to protect users against an email impersonating Google Docs, and have disabled offending accounts. We've removed the fake pages, pushed updates through Safe Browsing, and our abuse team is working to prevent this kind of spoofing from happening again. We encourage users to report phishing emails in Gmail."

Google has issued a second update detailing what happened and how it's protecting users from such exploits: