Phone-to-email Spam

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Can I send you an email?

In the last few months there has been a rise in “pretexting” phone calls from legitimate marketing organisations, probably in response to anti-spam legislation around the world.

The usual script is an unsolicited phone call from a real live human, asking for permission to use your email address in order to send you some marketing material, usually described as a “White Paper”.

The calls are often made over a low-quality connection (i.e. cheap VoIP) and come from non-native English speakers (a kind way to suggest “offshore call centres”). However, they do generally respond well to a polite “No thanks” as an answer, and to requests to not be called again in the future. If permission is given the eventual email usually represents a legitimate trading company of some sort.

All in all, no real problem.

I have a business opportunity for you!

However, we’re beginning to hear of the same approach being used by spammers, particularly of the advance-fee fraud variety. A small amount of research (i.e. get your name and job title from a website), a hacked VoIP system (which lets them call anywhere in the world for free), and a fresh email address from one of the big free webmail providers potentially gives these criminals a much more direct line to your mailbox and your attention.

This is a particular worry because it won’t be long before these techniques are used for distributing fresh malware – you receive a difficult-to-understand phone call from someone with urgent information to send to you, and a couple of minutes later in comes the email, along with a juicy PDF attachment. Would you resist the temptation to click? How can you tell the difference between an attack, and a real foreign student or academic trying to work with the University?

(Some of you reading this might suddenly realise that you already open too many attachments without stopping to check fully the source!)

What should you do?

The best defence if you are unsure would be to check with your colleagues, see what they think; to check with your IT support; or to ask the ITS Information Security Office for an opinion.

If you don’t have an opportunity to get a second opinion, you have a few technical opportunities to reduce the risk. Firstly, wait a while … come back to the message in a couple of hours time. If the message came out of hours, just don’t open it until you are back at work. Remember that just because it seems to be urgent to someone else it is not necessarily urgent to the University!

Instead of just opening the attachment, ask your anti-virus software to scan it. This is best combined with the “wait a while” approach – if this is a new malware sample (there are tens of thousands per day automatically created), give your AV software time to get an update from the vendor.

Finally, open the attachment in an unusual program. For example, malware PDFs often only successfully attack Adobe Acrobat Reader, so if you have a different PDF reader available you could use that. Instead of opening untrusted attachments with Microsoft Word, open it with a copy of Libre Office. If your job role means that you will be receiving unsolicited attachments regularly, get your IT support to help you install these alternatives.

Finally, if you are in any doubt, leave the file alone and refer the whole thing to the Information Security Office. We can check a lot more details to find out what is going on, and we really don’t mind being asked.

This entry was posted in Education, Incident Response, SPAM/Phishing, Viruses/Malware by Jim Cheetham. Bookmark the permalink.

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