Category: Security

How to know whether it’s safe to click a button in an email

How to know whether it’s safe to click a button in an email

When I got an “urgent” email the other day from a colleague asking me to enter some data in a Google form, my warning bells started to go off. Whenever I’m told that something is urgent, I get suspicious.

It turned out to be kosher, but it made me realise I don’t know how to verify whether a request to complete a Google form is valid or not.

The email contained an embedded “Continue” button. I couldn’t hover over it to find what url it was visiting. I tried “View Source” in the browser, but what I got contained several different urls, none of which were easy to recognise, and the whole html chunk was difficult to parse.

When I finally did throw caution to the winds and click on the button, I got a warning: “You are submitting information to an external page. Are you sure?”… but still, I had no idea how to verify that it was safe.

But of course, the great thing about working for ThoughtWorks is that I have access to a global pool of talented technologists, and it didn’t take long for someone (my colleague Andy Yates: to answer my query.

Big proviso: it’s not a simple business to verify these things. If you are not technical, and even if you are, you should report any suspicions to the relevant people in your organisation. They will be happy to help and would rather have a false alarm than miss a malicious phishing campaign targeting your company.

Here is Andy’s advice:

“I believe there are a couple of things that help show that it’s a genuine request:

– the email address that the form is from is (and checking the ‘show original’ confirms it really is the from / return-to address, and that there is an SPFand DKIM pass)

– at the top of the email there is a link ‘having trouble: fill out in google forms’ – this *can* be hovered over, and from here you can see it’s a genuine google forms URL

– (personally, if I was suspicious, I’d follow that link, and skip the button, which doesn’t help speed things up anyway)

– if you have developer tools enabled, you can use ‘inspect element’ to see the form that the submit button is attached to, and you can check the domain of the URL from here too – I find this is a bit easier than doing ‘view source’ because it navigates to the right spot

– if / as you do click through, at the very bottom of the form it states “This form was created inside of ThoughtWorks.” (for other domains it would write out the domain in full)

– (you can also check this by trying to open the same form from an incognito window, where (in this case) you won’t be able to access it, as it’s private to our domain)

– (I put this last one in brackets, because I’m not convinced that it is proof of a legitimate message. I think it *might* be possible to create a form for a similar domain and share it to our domain – so it would look to someone incognito like it was domain-private, but it would in fact say something like “This form was created inside of” instead of “… ThoughtWorks.” to us)”