outlook – PwnDefend

Business Email Compromise Check List

As part of my Cyber SOC GitHub repo I’ve put together lots of resources to try and help people with some common cyber security tasks, applicable to CISOs through to SOC analysts.

I also want to highlight one of the most common incident types if you are an Office 365 customer is a business email compromise scenario, so I’ve put together a high level view of the steps you might want to take after a BEC event is discovered:

Vulnerabilities

Microsoft Outlook Elevation of Privilege Vulnerability (CVE-2023-23397)

Regarding: CVE-2023-23397

This is a fast publish, use at own risk.

See guidance from Microsoft: CVE-2023-23397 – Security Update Guide – Microsoft – Microsoft Outlook Elevation of Privilege Vulnerability

If you need to mitigate the latest Outlook vulnerability which abuses an SMB/WebDav call using the Calendar invite feature you can consider the following:

Education

The Long Game: Persistent Hash Theft

CVE-2023-23397 enables a threat actor to send a calendar invite whereby the properties of the msg file can include a path for the reminder sound file. This is achieved by setting:

Guides

Reporting an email as phishing in Office 365 with…

Did you ever just ignore or delete a phishing email? I mean that’s great in one sense that you won’t have any negative impact. But if the email did get past the mail security filters, you can report it using the “Mark as phishing” option.

What if as well you wanted to not only enable users to report but also pass the intelligence onto the NCSC Suspicious Email Reporting Service (SERS)? How cool would that be! Well, have no fear people, we are going to show you how easy this stuff is to deploy and configure. Read more “Reporting an email as phishing in Office 365 with NCSC SERS” →