SPAM

What is spam

Spam email is typically unsolicited and unwanted junk email sent to random recipients.  Spam is usually sent in large volumes by automatic sender programs, sometimes from 3rd party computers.

Spam may simply be in the form of advertisements for goods or services.

Government advice

You can get more detailed advice at the National Cyber Security Centre.

Why do spammers send out spam?

It is usually sent out to try to get the victim to pay for something, to gather information about them or to extract information from them or their computer. You may even be asked to download a program disguised as a .PDF. If you open some downloads, teh scammer can install remote access to your PC and when you are not using it, they can have the same access to it as you do. So they have access to all your stored passwords and can run further data extraction programs.

How do I recognise spam?

It is actually very difficult to spot the really good ones and I cant offer any firm rules for doing so as there are too many variations.

Hover over the links in the email and see where the link takes you – if it is any way suspicious, take precautions.

How can I stop spam?

You cant stop anyone sending you spam but you may enable filters in your mail client or enable spam filtering at your mail server. Megganet use a variety of mail severs, each with a different system for identifying spam and each with different method of configuring your mail client.

How do they get my email address?

Spammers use a variety of techniques to acquire your email address such as;

• Spider programs trawling websites. Instead of putting an email address in text on a website (which can be red by spiders), some web designers put a picture of an email address on the website.
• Using guessable email addresses such as info@domain.com and accounts@domain.com are good for organising your email when several staff have access to a single account but easy for a spammer to guess. For shops we use shop@domain.com and for dentists we use something like smile@domain.com
• Planting a virus or email address trawler on your computer. A good virus checker will stop this.
• Reading email on a compromised computer. If you send an email to somebody, it will land on their device. If their device is compromised, spammers can take your email address directly from their device.
• Listeners. When you send your email, it travels through the internet. There may be listeners, checking your data stream programmed to detect email addresses. Not just yours but all the people in your group. Once they detect a group of email address, spammers can take one email address out of the group and use it to send other members of the group spam. When the victim receives an email from someone they recognise, they are more inclined to open it and boom.
  
  

How a spam rating is set

Every email is sent from somebody to somebody. The email sets out from the senders email program, through their router, onto the internet, to the senders mail server, then on to the recipients mail server where it waits to be viewed or downloaded, eventually it lands on the recipients computer – into Outlook or other mail client. At any stage it might get classified as spam and at most stages, it will receive a spam rating in the form of a number. The higher the number, the more likely the email could be classified as spam.

If the senders computer sends out large amounts of email, the senders computers spam reputation goes up. Spam is usually sent out in large volumes but a computer sending out regular email is really only going to send out a very small number of emails at a time. This will increase the spam number.

If the computer the sender uses has a virus, it may attach a payload to the email on its way onto the internet. If any of the mail servers spot this, the email will be flagged as unsafe or spam and may be deleted. This will increase the spam number.

If there is a computer or device on the same network as the email senders computer which has been sending spam then any email sent through that internet connection may be classified as spam. This is because the internet connection has an IP which will get a bad reputation and any device using the same IP gets tared with the same brush. This will increase the spam number.

If the sender comes from a country which has a bad spam reputation then the email will automatically attract a spam number.

An email is made up of 2 parts, the prefix and the domain. The prefix is the bit before the @ in an email address. If the domain has been hacked, any email using it will have a spam number. If the domain is hosted on a domain server which has other domains and one of them is hacked, the email will get a spam number. If the IP the domain name is hosted on is linked to spam or bad web sites, then the email gets a spam number.

SPF and DMARC

It is possible to avoid some of the problems by inserting a SPF record into your domains DNS settings which helps identify the sender as legit. DMARC is another technique used to identify legitimate senders. Not all systems are compatible with these security measures and can cause problems of their own.

Unsubscribe

Sometimes the lesser harmful spam will have an Unsubscribe option which you can select and might work. However, many will simply start sending you different types of spam.

False positives

The stronger the spam filter the more false positives it will detect. So please check your spam folder in case you have missed a legitimate email. If you have, make sure to add the sender to your safe senders list. If you have access to your email control panel at domain level, you may need to whitelist legitimate email addresses there.