A new attack on Facebook users is a cunning combination of social engineering, Trojan horses, and botnets, according to researchers who’ve been studying it.

The new phishing email, which masquerades as a message from Facebook, promises to give users a new and easier login process. The “new login system” is thoughtfully sent with the user’s username already filled in, researchers say. All the user has to do is “give your password to update your account.”

According to a blog by researchers at security company AppRiver, the phishing attack has been spotted on smartphones using Facebook applications, where it carries the actual Facebook logo.

AppRiver says the attack emanates from the Zeus botnet, and researchers are seeing “Facebook phishing emails at a rate of about 1,000 messages per minute per domain used, with about 30 domains being utilized. That’s 30,000 messages per minute from this botnet, or 500 per second. On top of that, we’ve already seen about 1.65 million messages from this campaign.”

In some cases, the exploit has been seen as an official Facebook message that asks the reader to click on a link to receive an updated Facebook password. Clicking on that link causes the user to download the Bredolab Trojan, according to researchers at MX Lab.

This is just another example to show that everyone needs to be very careful when emails arrive in your inbox claiming to need a login or change of password. This type of thing is very rare to just send to your email without you requesting it so I would advise anyone who thinks that you may have seen an email like this to delete it and mark it as spam right away!