Microsoft has announced a new security policy for Outlook that blocks inline SVG images, responding to a rise in phishing and malware attacks using this file format. The change is already live for Outlook for Web and the new Outlook for Windows, representing another step in Microsoft’s ongoing efforts to keep users safe from cyber threats.
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What Are SVG Images and Why Are They Risky?
SVG (Scalable Vector Graphics) images are a popular web format because they scale without losing quality. However, unlike static files, SVGs can contain scripts and code. This makes them a target for attackers, who use SVGs to hide malicious code and launch phishing campaigns.
Recently, hackers have sent emails using inline SVG images to display fake login forms, trick users into clicking dangerous links, or deliver malware. Attackers enjoy this method because many email systems have supported inline SVG display until now.
How Is Microsoft Outlook Changing?
Microsoft will no longer show inline SVG images directly in email messages for users on Outlook for Web and the new Outlook for Windows. Instead, users will see blank spaces where the SVG images would have appeared. SVG images that are attached as regular files remain safe and viewable from the attachments pane.
This targeted block is designed to cut down on one of the tactics cybercriminals use without disrupting general communication or image sharing. According to Microsoft, fewer than 0.1 percent of images in Outlook use inline SVG, so most users will not see any difference in normal email workflows.
What Are the Wider Security Measures?
This move is part of a larger campaign by Microsoft to reduce the risk of phishing, malware, and other attacks in its ecosystem. In recent years, Microsoft has:
- Disabled macros and add-ins by default in Office products
- Blocked or restricted risky file types such as .library-ms and .search-ms
- Added protections around Excel macros, untrusted ActiveX controls, and VBScript
- Implemented new controls for untrusted attachment types and cloud-based file sharing
These incremental changes aim to remove features that attackers have exploited, making Microsoft’s products safer for personal, business, and government use.
Impact on Users and Businesses
For most people, Microsoft’s update brings additional protection with minimal disruption. Trusted SVG attachments are still accessible, and popular image types for business and personal communication are not affected. The key takeaway for security teams and IT administrators is that even small changes in supported file formats can block entire classes of attacks.
Email remains one of the most common entry points for cyber threats, so proactive steps like this are critical for safeguarding sensitive information and keeping threat actors at bay.
What’s Next in Outlook Security?
Microsoft is expected to keep reviewing and updating its policies as phishing tactics evolve. The company actively monitors how attackers adapt and is committed to closing gaps as they appear. Users can always check Microsoft’s documentation for the latest on supported and blocked file formats.
By limiting opportunities for hackers to exploit email features, Microsoft is working to build a safer digital environment. Users should stay up-to-date with these changes, avoid clicking suspicious links or attachments—even from familiar contacts—and rely on built-in protections to minimize their risk.
