Phishing attacks have reached new levels of sophistication in 2024 and 2025. Cybercriminals are now leveraging AI to craft emails that look nearly identical to legitimate messages from trusted companies. In one recent campaign, attackers impersonated Microsoft 365 security alerts, successfully tricking users into surrendering their login credentials.
These attacks pose a serious threat to businesses of all sizes. A single deceptive email can lead employees to unknowingly share financial details, customer records, or internal account information with cybercriminals. The danger lies in how convincing these messages appear, often mimicking trusted sources or even high-level executives within the company. As a result, team members may not think twice before disclosing sensitive data.
Despite growing awareness and training efforts, phishing remains one of the most common and damaging forms of cybercrime in 2026. It often serves as the entry point for larger attacks, costing Australian organisations millions in losses, reputational damage, legal exposure, and operational disruption.
That’s why defending your business against phishing is no longer optional, it’s essential. While there are many tools designed to reduce this risk, Microsoft 365 Defender stands out with its multilayered approach to detecting, blocking, and mitigating phishing threats.
Seven Key Features of Microsoft 365 Defender
Phishing Email Protection
The most dangerous phishing scams are those that appear to come from legitimate sources. Attackers use clever tactics, like addressing victims by name or even hijacking real accounts to make their messages seem authentic and trustworthy.
Microsoft 365 Defender uses machine learning to analyze your communication patterns and identify the contacts you interact with most. By comparing normal behavior to suspicious activity, it can accurately detect and block phishing emails before they reach your inbox.
Malware Defense
Different types of malware can spread through phishing emails. For example, ransomware locks your files and systems until the attacker receives a ransom.
Spyware can be even more dangerous. It steals your information by copying clipboards, taking screenshots, or recording keystrokes.
Microsoft Defender 365 addresses such malware with robust safety mechanisms, namely:
- Layered malware defense – The platform comes with multiple malware scan engines to help diagnose potential threats. They provide a robust heuristic inspection to shield your system even in the earliest stages of an outbreak. This type of protection is superior to using just one anti-malware program.
- Real-time response – During outbreaks, the platform provides your team with instant access to devices, allowing you to investigate and contain threats in real-time. It also enables your team to collect data and proactively tackle malware.
- Rapid definition deployment – The Microsoft 365 Defender team maintains a close relationship with anti-malware engine developers. Consequently, users of the platform receive malware definitions on time. Plus, the company checks for definition updates every hour to help protect you against the latest malware.
- Common attachments filter – Some file types aren’t meant for emails, such as executable documents. With that in mind, the common attachment filter lets you automatically block them without any scanning. Some of the file types it can remove include .ace, .exe, .app, .ani, and .scr.
Spam Block
Another common culprit for phishing campaigns is spam emails. Blocking them is an excellent way to shield your organization from attacks.
Defender boasts powerful anti-spam technology to address spam emails by examining the source of the message and the contents. If the email comes from untrustworthy sources or contains suspicious information, it automatically goes to your spam folder.
On top of that, this feature examines your team members’ activity to help make sure they don’t send spam emails to other users.
Safe Links
Phishing emails don’t only contain attachments. They can also include URLs to lead your team members to a fraudulent website.
These web pages often look legitimate, but they generally require the victim to provide some information. Furthermore, they can lead to websites that install or download malware on your computers.
Safe Links shield your system from malware transmissions using URL detonation. It scans email links and checks for suspicious behavior.
Microsoft Defender 365 warns you not to visit links that open malicious websites. Otherwise, you can open your destination URLs normally. It’ll also rescan the service sometime later and look for any security problems.
Another great thing about this feature is that it scans email links from all personnel within your organization. Moreover, it works great on documents uploaded to SharePoint and Microsoft Teams.
Sandbox Isolation
Some users, especially if they’re reckless, commonly open malicious email attachments without second thoughts. They can expose company data to prying eyes as a result, which can ruin your reputation and give your competitors the edge.
Defender can reduce this risk by opening all email attachments in a sandbox. It serves as isolation, meaning that malicious files can only affect the sandbox rather than your system.
Once the program isolates malware, it’ll warn you not to open it. But if the attachment is safe, you’ll be able to use it normally.
Enhanced Filtering
Enhanced Filtering is perfect for enterprises that route emails to on-premises environments with third-party services before sending them to Microsoft 365.
The platform comes with inbound connectors that verify whether your email sources are trustworthy. The higher the complexity of the routing scenario, the higher the chances are that email connectors don’t reflect their real source.
What’s more, this feature preserves the authentication signals that may have disappeared while routing emails. It enhances the filtering capabilities of Microsoft 365, allowing it to detect phishing and spam emails more effectively.
User Submissions
Microsoft Defender lets you set specific mailboxes where you can send any threatening emails.
This feature allows you to determine the criteria for safe and malicious email while identifying the mailboxes that will store these messages. Thus, your administrators have more control over flagging emails and reporting them to Microsoft.
Stronger Security. Smarter Detection. Microsoft 365 Defender
Phishing attacks can cause serious trouble for your business, from data breaches to financial loss. One way to strengthen your defenses is by equipping your office computers with Microsoft 365 Defender. It delivers reliable protection, detecting and blocking threats before they can spread or compromise your data.
Of course, Microsoft 365 Defender is just one part of a well-rounded cybersecurity strategy. At NSN Infotech, we provide end-to-end cybersecurity solutions designed to align with the Essential Eight framework and protect your business from evolving threats. Learn more about our Microsoft 365 services.
