Should I be worry after opening suspicious Email attachment?

Question

Yesterday, I have received this following suspicious email

Normally, I would not click on any of the email attachments if I am not sure about the origin of it. But yesterday, I accidentally opened it.

Just to make things clear, I don't recognize the name of the person sending it and I am not expecting any receipt of payment of any kind at the moment. Also, to make things more suspicious, the sender was using a gmail account. If it were for business purpose, all of my contants would use legit company email (eg. [email protected]).

When I opened the attachment file, all I can see is a blank page on both firefox and chrome.

Since the file is in .htm format and not an executable nor zip file, should I be worried that my computer/email is compromised?

UPDATE 1: This is the content of the attachment file:

I am on windows 8.1 64bits, no anti-virus is installed.

UPDATE 2: What actions should I take so that I can use my laptop safely again? Such as doing on line banking transaction? Note: I do not have any IT personal to access at the moment. So the most, I will have to re-install the window/ reset the window(windows 8.1 feature) ?

Solution 1

You should get and install good anti-virus software before you do anything else. Run a full scan and you will find out the scale of the problem.

You should never run without anti-virus and firewall protection, unless you never connect to the internet or run software without being 100% certain that it is virus-free.

Solution 2

Without access to the malicious attachment, there really is no way to tell; but yes, I would be slightly worried. There is rarely a legitimate reason to send a forged email with an attachment.

Another question entirely is whether your system was vulnerable to whatever exploit they were trying to pull off -- the world is still full of Windows XP boxes, and many of the prevalent campaigns still try to focus on this extremely low-hanging, rotting fruit.

If you are one of them, I would certainly advice you to unplug immediately and start to plan mitigation. A good first step would be to not plug your computer back in to the network until you have a better picture of what happened. Copy interesting stuff to a USB stick and proceed with caution from a different computer (use an internet café or whatever -- don't surf from your zombie box).

Comments

[Ramhound]

Yes; If you opened the file within a browser; You should indeed be worried. I would get the help of your IT staff to help you verify what it did exactly.

[I say Reinstate Monica]

You can scan the file attachment at <www.virustotal.com> which will run it through 50+ virus scanners. While I would not consider the results conclusive, if you are told the file is malicious you'll at least have proof. That said, the file is malicious: 1) You don't know the sender, 2) you never made a payment for which you're expecting a receipt, 3) receipts aren't usually provided as HTML documents, 4) the .HTM file isn't an .HTM file of any interest to a human email recipient.

[Chris Aung]

@Twisty With my limited understanding, the java script from the browser do not have access to any of the file on the harddisk and all it can steal is cookies?Currently, I am wondering how much could that script cause harm to my system?

[I say Reinstate Monica]

@ChrisAung Have a look at this article in which it states You can get infected by just looking at the contents of an attachment.

[I say Reinstate Monica]

It's also worth noting that our concern should not be limited to what malicious code can do if it follows the rules, but rather what it might do if it breaks the rules (e.g. by leveraging an exploit).

[I say Reinstate Monica]

FWIW, Windows 8 does include Windows Defender out of the box.