[willvarfar]

And stop people emailing screen shots?

The best approach I can come up with after five seconds thought is disabling links on non-text elements.

And then they go make an anchor that is whitespace over top of a background image... so we'd also need to disable links on large expanses of empty whitespace in text when its embedded in a mail.

I should think that can likely be worked around too, however. Got any more ideas?

[swiley]

Far better would be to not render HTML emails at all. They're an abomination and have always been causing security problems of different kinds.

[sethrin]

> All programs will attempt to expand until they can render HTML emails. Those that cannot will be replaced by those that can.

More seriously, the expectation that emails will consist only of plain text is simply untenable. From a security standpoint this is obviously not ideal, but security and usability are opposed, and if your security scheme does not allow users to send documents with some form of markup, it will not be widely used.

[swiley]

Emails had a form of markup before HTML emails came, it was the inspiration for markdown.

[Mtinie]

For an "ultra security mode" that would work, but it would break a large portion of the Web's sites (as you noted, and it's easy-ish to circumvent) :/

Conceptually I like the idea of an ultra security mode for certain use cases, but ultimately it ends up making the whole web look like a bunch of plain text emails -- no JS, probably no images (unless the are somehow sandboxed and displayed from a safe local store), links are fully visible, etc.

[xja]

I was think more of a specific mail scanning process for images that look exactly like UI elements, with some fuzzy match.

If it matches, flag it with the usual warnings.

It feels like there's at least the potential to explore options.

[das_keyboard]

Why don't just put a little frame around embedded elements like pictures, etc? Maybe with a little icon indicating the type.

[laumars]

That would break more legitimate HTML e-mails than the phishing it's aiming to catch. You might argue that it's worth the breakage but that would be a harder argument to sell to businesses.

Pragmatically I think Browsers disabling the rendering of data:text/html is a better approach. The breakage is minimal and it would catch more phishing attacks than just ones that originated from emails with images embedded.

[pavel_lishin]

According to our numbers, plain emails actually perform better than HTML emails when it comes to business mailings.

[laumars]

That's good to read but sadly that's a different point to the one I was making. Google would break a lot of legitimate emails if they make the changes to GMail that the GP was proposing. This would be an unattractive solution to Google as they are effectively breaking their "mail client" (in the broader sense of the term) in relation to their competitors and the benefits are limited to a specific type of phishing attack. So when Google way up the risk of annoying their customer base vs the securing them: this particular fix is unlikely to score high enough in the latter category to be worth the risk to the former.

[jcranmer]

Break the image into several layers and use transparency for the non-included bits. Or you could go full Acid2-like crazy CSS to generate the image from multiple, apparently innocuous elements.

[tdkl]

Yeah, more people needs to get scammed, then the media will advertise how it happened and how to prevent it. It's called learning and is a sign of maturity.

[xja]

To be frank I think that's a bit naive.

These attacks are a numbers game. There's a low cost to sending the emails and a much larger payoff.

Education helps, but it's still possible to catch people off guard, tired, new users etc.

Anything that can be done to flag these emails as spam, or increase the cost to the attacker helps.

[gearhart]

Whilst I agree with you that the issue should be addressed by mail clients, these emails are not a numbers game in quite the same way as usual spam.

Since they rely on attachments and subject lines that are drawn from an individual user's gmail account, they have to propagate through a network, and they can't be just mass-emailed. Anything that can get the ratio of people falling for this lower than 1/<avg addressbook size> will completely eliminate the issue.