Email: The often ignored factor in strong cybersecurity

With the rise of 'cool' new corporate chat applications like Slack, Microsoft Teams and Workplace by Facebook, email, that dependable but unsexy workhorse of business communication, is often low priority for IT teams allocating resources and budget.

However, despite these new applications, email remains the lifeblood of every organisation. Because of its importance, and the information it carries, email is a major target for cybercriminals looking to attack an organisation and its people.

According to the Verizon Data Breach Investigation Report, 65 per cent of malware infections linked to data breaches were installed via malicious email attachments. The same report found that seven per cent of users were successfully phished.

In some industries, the rate was even higher, with 13 per cent of users in manufacturing phished, and 10 per cent in healthcare. That statistic means that in a 1000-person-strong company, 100 users are going to open a malicious email and potentially click on a link that could lead to a data breach.

While email can be an attack vector used to gain access to sensitive corporate data via phishing or impersonation attacks (a type of phishing scam that targets high profile users like CEOs and CFOs), it's also a valuable asset on its own to attackers.

The reason is that email usually contains personal information, which can be used for identity theft, or to launch a phishing attack. A customer-facing organisation will receive hundreds, if not thousands of emails every day, each one containing personal identifiers.

On top of that, internal corporate email communications contain personal information about both the sender and the recipient including their names, title and other data like phone numbers and Twitter handles.

Each of those emails don't just disappear into the ether once it's been dealt with, either. For various reasons, including regulatory requirements or for better customer service, email will usually be kept in an archive for months, if not forever.

That's why it's absolutely critical to protect both email resources as they are sent and received, as well as the archives those emails will live in. Emails are a treasure trove for attackers, and need to be guarded appropriately.

Unfortunately, email archives are one of the last things that a corporate security operation thinks about. There is a distinct lack of understanding about what can be lost in an email archive hack.

Cybercriminals are after more than just money. Corporate data, intellectual property, employee credentials and customer information can all be profitable to an attacker. A business that loses its email archives is looking at a whole lot more than just lost revenue and unplanned downtime.

With many organisations moving to Microsoft Office 365 or Google's G-Suite, it's easy to assume the built-in protections provided by those platforms are enough, and that their cloud archiving services will fully protect collected emails in perpetuity. That's not the case.

 There are still significant volumes of phishing, impersonation attacks, and other emails containing malicious content.

A Mimecast Email Security Risk Assessment inspected 55 million emails that were passed by other security tools – and the results are astounding. More than 12 million – or close to a quarter – of the emails were in fact deemed 'bad'. It found 12.5 million spam emails, 9,000 dangerous file types, 2,500 malware attachments and 19,000 impersonation attacks.

What these tests demonstrate is that email is an attack vector, and that incumbent security systems aren't good enough at preventing an attack. So, what should organisations do? 

The answer for organisations wanting to maintain a strong cyber resilience posture is to employ a cloud-based email security solution. Look for a solution that provides protection against ransomware, phishing and impersonation attacks, as well as cloud archiving and email continuity.

However, while cloud email security solutions offer a rapid means of improving data protection, they are just one part of the bigger picture. A truly effective cyber resilience regime also requires protection of other parts of the enterprise.

Companies wanting to adopt best practices should look to the Australian Signals Directorate's Essential Eight and Top 4 guidelines, which include patch management and application whitelisting, among other pointers.

The introduction of Australia's Notifiable Data Breaches (NDB) scheme in February is an added impetus for organisations to get their email houses in order. The legislation has provisions for penalties of up to $1.8 million for non-compliance.

In addition to those penalties, there are also the reputational consequences of experiencing a data breach. Any organisation that loses emails will have to deal with customers taking their business elsewhere. The costs of not securing email and email archives are simply too high to ignore.