You’ve probably been warned about the risks of trusting emails from people you don’t know, and if you haven’t then our advice is to think twice before booking your dream holiday from an email claiming that you have won the lottery when you didn’t even buy a ticket!
But what about emails from your friends, colleagues, long-standing doctor or smart-suited solicitor?
When we receive a message from a familiar email account, then how many of us are likely to click on links or open attachments without paying as close attention as we would for an email from an unknown account?
As a NakedSecurity reader you are probably already aware of these risks. But what about your friend, your mother, your next door neighbour or someone you do business with?
Last week my solicitor had his email account hacked. Here’s what happened next.
The First Attack
For me it started with an email from my solicitor:
This came from his real (not spoofed) email address and included his normal email signature, with phone and address details. As I am in the middle of moving house and expecting paperwork from him, this email and attachment appeared completely normal at first.
As I moved my cursor to open the attachment I noticed a problem. The attachment was called
Drafted Contract003.pdf.htm – a cunning use of the double extension
.pdf.htm which was an attempt to trick me into thinking that this was a PDF document instead of the HTM (web page) file that it actually was.
On opening the file, instead of a PDF viewer launching, my browser opened with a popup alert:
After closing this alert I was taken to a very realistic looking Google login page:
The next clue that this wasn’t real can be seen in the address bar:
This address clearly isn’t Google, it isn’t even a website URL, but instead it is the code included in the HTM file. This code can be seen if you open the HTM in a text editor:
If you look at the source code of this page in a browser you can see that any user who enters their username and password will have those details submitted to the hacker and not Google.
At this point I contacted my solicitor and alerted him to the fact that his email account had been compromised and it was sending phishing emails. He thanked me and took my advice in changing his password and contacting his customers to advise them to be on the lookout for suspicious emails.
But that wasn’t the end of it – the next day I received another email.
The Second Attack
The new email had the same signature and appeared to come from my solicitor; however, this one actually came from a random Gmail address:
This time it had a real PDF file attached called
Financial Statements001.pdf. On opening this file, a blurry picture appeared with a link at the top.
I haven’t altered this picture. It was blurred out by the crook so that most of the text is unreadable, leaving only the Barclays bank logo and an ‘Approved’ stamp legible. The idea is to trick you into thinking you have been approved for some kind of contract or loan and that if you click the link at the top you will be able to view the details.
In reality, clicking the link takes you to a web page hosted on the same domain as the previous phishing email, which again requires you to ‘log in’ on a fake Google page.
Looking at the
whois ownership information for that domain, I saw that it had been registered one week earlier using presumably fake or stolen personal details of a woman called Fiona in Lagos, Nigeria.
At this point it was clear that the hacker had not only got into my solicitor’s email account but also stolen all the contact details in his address book. This allowed the attacker to continue targeting me and other customers using the same details but from different email addresses.
I contacted my solicitor again to try and understand if he knew how his account had been hacked and what else had happened. It came as no surprise that he had recently received a similar email that had tricked him into entering Google login credentials. So he was phished, which led to the account compromise.
Now I wanted to understand the purpose behind the actions of the crook: was he just after usernames and passwords to sell on the Dark Web?
The answer became clear when I looked at the filters on his email account.
He had twenty new email filters named
C… all the way through to
T. Most of these had a similar theme: any email containing a keyword in the subject or message, such as
Sort Code would be moved into a
Recently Deleted folder.
For hackers working against the clock, aware that the victim could change their password at any moment, this would make it very quick for them to get hold of the most valuable emails and save them for further investigation later.
The last few filters targeted emails that contained references to
Contract003.pdf.htm. These would be automatically dumped into the
In other words, emails from me – and anyone else who tried to warn the solicitor that he had been hacked – would most likely have vanished into his
Spam folder and never been seen, giving the hacker more time to keep the scam going.
It would be easy to say at this point that the moral of this story is, “Don’t trust anybody”, but I don’t want to be that dramatic.
Because it’s Cybersecurity Awareness Month, I’m going to leave you with more usable advice: STOP. THINK. CONNECT.
Even a couple of seconds of thought before opening attachments or clicking on links can save you from all sorts of unwanted attention from cybercriminals.
What to do?
To protect yourself from emails sent under false pretences by crooks:
- Look out for emails that come from different addresses to what you’d expect.
- Be careful of documents that ask you to enable macros or editing before you can see the contents.
- Tell Windows Explorer to show file extensions to protect you against misleading filenames.
- Watch out for double file extensions (e.g.
.pdf.htm) or extensions you aren’t familiar with (e.g.
- Hover your mouse cursor over links to see if they go where they say they are going.
- If in doubt, call or speak in person to your friend or colleague and ask them if they sent the email. (Don’t use the number in the email you’re concerned about – look the number up in a different way!)
To protect yourself from having your email taken over by crooks to attack your friends and customers:
- Pick proper passwords. Even though strong passwords don’t help if you are phished (the crooks get the strong password anyway), they make it much harder for crooks to guess their way in.
- Use two-factor authentication whenever you can. That way, even if the crooks phish your password once, they can’t keep logging back into your email account.
- Consider using Sophos Home. Our free security software for Mac and Windows blocks malware and keeps you away from risky web links and phising sites.
16 comments on “Why you should be cautious of emails from friends or colleagues”
Liked this article and the timing was right on. I’ve been receiving many of this type of email and so far haven’t fallen for the scams. The article was written in easy-to-understand language. Thanks.
This is all fine and dandy, but you make no reference to the CONTENT of the ëmails.
Does your solicitor normally address you as ‘Dear sir’, capitalise ‘Contract’ or use phrases like ‘Please confirm that all is in order’?
Does your solicitor normally greet you with ‘good day’ and attach things ‘for your perusal’?
If not, surely the scam falls at the first fence.
Even if that didn’t happen in this case, using linguistic hints only gets you so far.
Firstly, for the many non-native users of English in the Anglophone world, such distinctions are hard to learn, even for fluent speakers. Secondly, many business emails aren’t well-written, sadly, so even careless crooks often don’t have a lot to aim for. And thirdly, if the crooks have your email password, they can copy and paste your way of writing exactly just by using earlier emails.
So, use linguistic hints if you can, but don’t rely on them too much because the crooks are learning how to copy well-written emails and thus look a lot more realistic than in previous years…
Linguistic hints are valuable for setting off a flare in ones mind. But, they shouldn’t be used as a way of validating emails.
This just goes to show how easy it is to fall for these attacks and how advanced they are. When checking links in emails, by hovering the mouse over the link to reveal the link address, is there a simple way to spot case sensitive tricks? E.g. googIe.com where the L character is an uppercase i thus googie.com? Perhaps the domain portion of the address could be forced to display lowercase. I’m unaware if this is enforced in mail or browser apps
If I want to make sure, I copy and paste web site text into my text editor, where I use a monospaced font designed for clarity, so no two letters look so alike that they can be confused.
Same here. But can we expect and encourage non savvy users to do this? For every link? Apps could help by enforcing lowercase domain names….
It seems to be a “presentation layer” problem to me. The modern era favours san-serif fonts with very lean glyphs that lend themselves to confusion, notably lower-case L and upper-case i.
Perhaps we need to take a leaf from the road transport experts – many countries have taken great care to choose road sign typefaces that are easy to read and not prone to confusion, as well as looking modern and clean.
Same thing with number plates. The countries of Southern Africa, for example, have standardised on a font where no characters can easily be “adapted” into others with black markers or tape, and where characters are difficult to confuse. Zero and oh are visibly different; eye and one are distinct; C can’t be extruded to look like G; and so on. Once you’re familiar with the shapes you won’t easily misread a plate.
Upon setting up a new install of any system, I make sure to set my system wide fonts to use Times New Roman or Courier New, as this will allow you to notice the substitution of 0 (zero) for O (letter oh) and other switches used to mimic domains by crooks.
How can I get software for Mac that automatically deletes my emails after they are opened?
You don’t need any special software. Setup a RULE in the MAIL application. It is under Mail->Preferences->Tab Rules press the (+) do add a new rule.
Along with changing one’s free email accounts passwords, changing the passwords on any other account re-using that same password is strongly recommended. Having unique passwords per site is a pain, but will save the data you entrust on your financially and personally sensitive sites.
At the heart of what is comfortable in our online lives, hide the keys to bypass our common sense.
Surely this is an argument for treating routers as PCs and putting security software on them which frequently and regularly updates with blacklists for inbound and outbound domains.
I believe you are referring to synchronised security…
Wondering if we can even trust e-mails from Sophos Naked Security these days. For the past few weeks Thunderbird e-mail has flagged every Naked Security as a potential scam. I’m sure it’s a mistake, but it does make you wonder what the heck they are putting in the e-mails to cause them to be flagged like that.
If you’re sure it’s a mistake – and we agree it is 🙂 – it would be nice if you could report this to Mozilla. I’ve not heard of any other community blocklist or free mail service routinely blocking our newsletters.
As well as wondering what we put in them (which is a matter of public record – you gave the entire email, after all), it’s worth wondering what Thunderbird is looking for…because that’s something that we can’t easily figure out (and may depend on your own configuration, anyway).