Security News

We're not quite sure what to call it right now, so we referred to it in the headline by the hybrid name Microsoft Office 365. The web-based versions of the Office tools don't have the same feature set as the full apps, so any results we might obtain are unlikely to align with how most business users of Office, ah, 365 have configured Word, Excel, Outlook and friends on their Windows laptops.

WithSecure researchers are warning organizations of a security weakness in Microsoft Office 365 Message Encryption that could be exploited by attackers to obtain sensitive information. OME, which is used by organizations to send encrypted emails internally and externally, utilizes the Electronic Codebook implementation - a mode of operation known to leak certain structural information about messages.

Security researchers at WithSecure, previously F-Secure Business, found that it is possible to partially or fully infer the contents of encrypted messages sent through Microsoft Office 365 due to the use of a weak block cipher mode of operation. Organizations use Office 365 Message Encryption to send or receive emails, both external and internal, to ensure confidentiality of the content from destination to source.

Resecurity, a Los Angeles-based cybersecurity company protecting Fortune 500 worldwide, identified a new RAT advertised in Dark Web and Telegram called Escanor. The threat actors offer Android-based and PC-based versions of RAT, along with HVNC module and exploit builder to weaponize Microsoft Office and Adobe PDF documents to deliver malicious code.

This article will explain why users should block macros in Internet downloads and how you can block them in Microsoft Office. To prevent this distribution method, Microsoft announced in February that Microsoft Office would automatically block VBA macros in documents downloaded from the Internet starting in June.

A "Dangerous piece of functionality" has been discovered in Microsoft 365 suite that could be potentially abused by a malicious actor to ransom files stored on SharePoint and OneDrive and launch attacks on cloud infrastructure. The cloud ransomware attack makes it possible to launch file-encrypting malware to "Encrypt files stored on SharePoint and OneDrive in a way that makes them unrecoverable without dedicated backups or a decryption key from the attacker," Proofpoint said in a report published today.

Security researchers are warning that threat actors could hijack Office 365 accounts to encrypt for a ransom the files stored in SharePoint and OneDrive services that companies use for cloud-based collaboration, document management and storage. A ransomware attack targeting files on these services could have severe consequences if backups aren't available, rendering important data inaccessible to owners and working groups.

Follina abuses Microsoft Office to execute remote code. CVE-2022-30190, also known as "Follina", is a remote code execution vulnerability that affects Microsoft Office, reported on May 27, 2022.

Microsoft Office apps - including Outlook and Teams - are vulnerable to homograph attacks based on internationalized domain names. "Users, who are trained to validate a link in an email client before they click it, will be susceptible to click on it because it has not yet been translated to a real domain name in their browser. The real domain name would only be seen after the page has started to open," Bitdefender researchers warned.

An advanced persistent threat actor aligned with Chinese state interests has been observed weaponizing the new zero-day flaw in Microsoft Office to achieve code execution on affected systems. "TA413 CN APT spotted exploiting the Follina zero-day using URLs to deliver ZIP archives which contain Word Documents that use the technique," enterprise security firm Proofpoint said in a tweet.