Email hardening

Detecting socially engineered messages

Socially engineered messages pose a significant threat to organisations. They can have a big impact, helping malicious actors access accounts, systems or sensitive information. Learn how to spot a socially engineered message, including through email, SMS, social media or messaging apps.

How to combat fake emails

Organisations can reduce the likelihood of their domains being used to support fake emails by implementing Sender Policy Framework (SPF) and Domain-based Message Authentication, Reporting and Conformance (DMARC) records in their Domain Name System (DNS) configuration. Using DMARC with DomainKeys Identified Mail (DKIM) to sign emails provides further safety against fake emails. Likewise, organisations can better protect their users against fake emails by ensuring their email systems use and apply SPF, DKIM and DMARC policies on inbound email.

Implementing certificates, TLS, HTTPS and opportunistic TLS

Transport Layer Security (TLS) is a widely used encryption protocol which enables parties to communicate securely over the internet. Through the use of certificates and Public Key Infrastructure (PKI), parties can identify each other through a trusted intermediary and establish encrypted tunnels for the secure transfer of information.

Malicious email mitigation strategies

Socially engineered emails containing malicious attachments and embedded links are routinely used in targeted cyber intrusions against organisations. This publication has been developed to provide mitigation strategies for the security risks posed by these malicious emails.

Marketing and filtering email service providers

This publication provides high level guidance on how to use email service providers (ESPs) in particular deployment scenarios. The considerations and controls described in that publication also apply to ESPs sending email on other organisations’ behalf.

Microsoft Exchange Server security best practices

This paper—authored by the National Security Agency (NSA), Cybersecurity and Infrastructure Security Agency (CISA), Australian Signals Directorate’s Australian Cyber Security Centre (ASD’s ACSC), and Canadian Centre for Cyber Security (Cyber Centre)—provides security best practices for administrators on hardening on-premises (on-prem) Exchange.

Protecting against business email compromise

Business email compromise is when malicious actors use email to abuse trust in business processes to scam organisations out of money or goods. Malicious actors can impersonate business representatives using similar names, domains or fraudulent logos as a legitimate organisation or by using compromised email accounts and pretending to be a trusted co-worker.