Monday, April 15, 2024

Important Security practices for users to Open Microsoft Office Documents Securely

Microsoft office documents utilized in wide by attackers to send the malicious file and then convincing the user to open the file with social engineering methods.

With Microsoft, there are several methods to exchange data between applications and the most popular one is DDE know as Dynamic Data Exchange which sends messages between applications and uses shared memory to exchange data between applications. It can be used for onetime or for continuous exchange.

Here you can see the video Tutorial for DDE Exploit done by our Team.

Hackers using this method in wild to execute malicious scripts and to compromise victims. Microsoft released best security practices on how to safely open Office documents that contain Dynamic Data Exchange and strongly recommends to review the security feature.

In an email attack scenario, an attacker could leverage the DDE protocol by sending a specially crafted file to the user and then convincing the user to open the file, typically by way of an enticement in an email. Microsoft said.
The attacker would have to convince the user to disable Protected Mode and click through one or more additional prompts. As email attachments are a primary method an attacker could use to spread malware, Microsoft strongly recommends that customers exercise caution when opening suspicious file attachments.

Recent MS office Remote Code Execution Vulnerability allows an attacker to take complete control of infected Windows Operating System and this vulnerability has been affected with all version of Microsoft Office. It was addressed by Microsoft with security advisory CVE-2017-11826.

Also Read Exploiting Windows Using Microsoft Office DDE Exploit (MACROLESS)

Mitigations for DDE attack – Microsoft

Microsoft Excel

Excel heavily depends on DDE to open documents, Microsoft suggests disabling Disable automatic update of Workbook Links to prevent auto updates from Excel including DDE, OLE.

If you disable Auto update then data will not be up to date, so the user needs to feed data manually. Applies to Office 2007, 2010, 2013, 2014.

To disable the DDE feature via the user interface:

Set File->Options->Trust Center->Trust Center Settingsā€¦->External Content->Security settings for Workbook Links = Disable automatic update of Workbook Links.

To disable the DDE feature via the Registry Editor:

[HKEY_CURRENT_USER\Software\Microsoft\Office\<version>\Excel\Security]
WorkbookLinkWarnings(DWORD) = 2

Microsoft Word – Office documents

For Office 2010 and above

[HKEY_CURRENT_USER\Software\Microsoft\Office\<version>\Word\Options]
DontUpdateLinks(DWORD)=1

For Office 2007

[HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Word\Options\vpref]
fNoCalclinksOnopen_90_1(DWORD)=1

Microsoft Outlook

For Office 2010 and above

[HKEY_CURRENT_USER\Software\Microsoft\Office\<version>\Word\Options\WordMail]
DontUpdateLinks(DWORD)=1

For Office 2007

[HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Word\Options\vpref]
fNoCalclinksOnopen_90_1(DWORD)=1

With windows 10 after fall creator update Windows Defender Exploit Guard able to block DDE-based malware within Attack Surface Reduction according to Microsoft.
Website

Latest articles

Hacker Customize LockBit 3.0 Ransomware to Attack Orgs Worldwide

Cybersecurity researchers at Kaspersky have uncovered evidence that cybercriminal groups are customizing the virulent...

Microsoft .NET, .NET Framework, & Visual Studio Vulnerable To RCE Attacks

A new remote code execution vulnerability has been identified to be affecting multiple Microsoft...

LightSpy Hackers Indian Apple Device Users to Steal Sensitive Data

The revival of the LightSpy malware campaign has been observed, focusing on Indian Apple...

LightSpy Malware Attacking Android and iOS Users

A new malware known as LightSpy has been targeting Android and iOS users.This sophisticated...

This Startup Aims To Simplify End-to-End Cybersecurity, So Anyone Can Do It

The Web3 movement is going from strength to strength with every day that passes....

Alert! Palo Alto RCE Zero-day Vulnerability Actively Exploited in the Wild

In a recent security bulletin, Palo Alto Networks disclosed a critical vulnerability in its...

6-year-old Lighttpd Flaw Impacts Intel And Lenovo Servers

The software supply chain is filled with various challenges, such as untracked security vulnerabilities...
Guru baran
Guru baranhttps://gbhackers.com
Gurubaran is a co-founder of Cyber Security News and GBHackers On Security. He has 10+ years of experience as a Security Consultant, Editor, and Analyst in cybersecurity, technology, and communications.

Top 3 SME Attack Vectors

Securing the Top 3 SME Attack Vectors

Cybercriminals are laying siege to small-to-medium enterprises (SMEs) across sectors. 73% of SMEs know they were breached in 2023. The real rate could be closer to 100%.

  • Stolen credentials
  • Phishing
  • Exploitation of vulnerabilities

Related Articles