Close specific vulnerabilities and generally reduce the attack surfaces of your Microsoft 365 and Office products! How can you do this? With professional System Hardening. In this guide, we explain what measures you need to take and which guidelines will help you best.
Microsoft 365 and MS Office must be protected!
Microsoft Word, Excel, PowerPoint and Outlook are used millions of times around the world – in schools, companies, public authorities and at home. This is precisely why Microsoft Office and Microsoft 365 applications are a popular target for cyberattacks.
Attackers often exploit typical vulnerabilities to infiltrate malware quickly and easily. Once the systems have been compromised, lateral movement and many other steps follow, which can cause a great deal of damage to companies.
Popular gateways are macros in documents or HTML content in emails. You should therefore make sure that these typical attack vectors have no chance. How can you do this? Through so-called Office Hardening.
What is Office Hardening?
Office Hardening refers to the Secure Configuration of popular Microsoft products in order to significantly reduce the attack surface of the software package. This gives users a secure digital environment and allows them to work with less fear of cyber incidents.
Office Hardening is therefore a discipline of broader System Hardening. Metaphorically speaking, this is about closing the doors and windows of your IT landscape so that criminals don’t stand a chance.
System Hardening in general and Office Hardening in particular requires a variety of measures. These can be very labor-intensive and time-consuming, as several hundred settings have to be adjusted per system. These need to be evaluated in advance in order to assess the impact on the software and its use.
Automation – for example with Enforce Administrator – is a much faster solution. With this hardening tool, you can centrally harden and manage both individual Office products and large, complex IT landscapes.
⏬ Download: Enforce Administrator Product Brochure (PDF)
How should Office programs be hardened?
There are various answers to this question. For example, the German Federal Office for Information Security (BSI) has published comprehensive recommendations for hardening Microsoft Office and the individual applications (Excel, Word, Outlook, PowerPoint, Visio, Access).
Office Hardening is also being addressed “Down Under”. On the website of the ACSC (Australian Cyber Security Center) there is a free and readable publication entitled “Hardening Microsoft 365, Office 2021, Office 2016 and Office 2016”. This is a very good addition to the blog post “Security Baseline for M365 Apps for enterprise v2412” from Microsoft.
In our opinion, the best guide on the subject of Office Hardening is the “CIS Microsoft Office Benchmarks”, published by the Center for Internet Security. The 600+ page document contains recommendations for the secure configuration of Microsoft Office 2016, 2019, 2021 LTSC and Office 365 Apps for Windows 11, Windows 10, Windows 8.1 and Windows Server 2016/2019/2022.
Office Hardening: overview and examples
The following measures form – from the point of view of the ACSC, the BSI, the CIS benchmarks and also our assessment – the basis for an effective and sustainable hardening of Microsoft Office. They represent essential protection mechanisms to significantly increase the security of programs such as Word, Excel or PowerPoint.
-
- Disabling VBA macros in Office documents
- Disabling HTML content in emails
- Blocking insecure ActiveX controls
- Restricting file downloads
- Reducing add-in management
- Controlling OLE objects and MIME
- Disabling telemetry data collection
- Disabling internet FAX and Connected Experiences
- Blocking OneDrive logins
- Use of digital signatures and certificates
- No permission for web add-ins
- No access to the Office Store
- Forcing automatic updates
- Enabling the Information Bar
- No execution of Flash elements
- Protected View for files from the Internet
Advantages: What are the benefits of Office Hardening?
The main goal of Office Hardening is to sustainably reduce the attack surface. This makes it considerably more difficult for attackers to misuse Microsoft 365 and Office applications as a gateway. You also put a stop to Microsoft’s “data espionage”. Unfortunately, the company has repeatedly attracted attention for collecting an unnecessary amount of customer information – such as telemetry data.
Hardening Word, Excel, Outlook, PowerPoint etc. ensures that the applications are more secure. Office Hardening is therefore an important part of a more comprehensive system hardening – and an essential component of an even greater IT security strategy.
Such a strategy encompasses these three areas: Prevention, detection and response. With professional System Hardening, you lay an important, preventative foundation. One that is required by more and more standards, regulations and IT laws, including ISO 27001 and the Digital Operational Resilience Act (DORA).
How do you check Office Hardening?
Does your Office Hardening comply with current recommendations? Do the check – with AuditTAP! You can download it from Github and use it free of charge in accordance with the license terms.
You can use AuditTAP to check individual applications such as Word and Excel and complete operating systems (Windows, Windows Server, Linux). A report shows you how well your target systems are hardened.
Then draw the right conclusions from the compliance report. And always remember: there is no such thing as 100% protection, even with the toughest Office hardening.
Conclusion
Office Hardening is one of many important steps you can take to improve IT security in your company. By consistently implementing proven security measures, you can close known attack paths and increase the resilience of your infrastructure to growing cyber threats.
Do you have any questions?
Want to know more about System Hardening? Or would you like to know how you can professionally realize (automated) System Hardening and implement it in your company? Contact us – our experts will be happy to help you!
Images: Freepik