#mac

A developing piece of ransomware called Big Head is being distributed as part of a malvertising campaign that takes the form of bogus Microsoft Windows updates and Word installers. Big Head was first documented by Fortinet FortiGuard Labs last month, when it discovered multiple variants of the ransomware that are designed to encrypt files on victims' machines in exchange for a cryptocurrency

Mitigation refers to a setting, common configuration, or general best-practice, existing in a default state, that could reduce the severity of exploitation of a vulnerability. The following mitigating factors might be helpful in your situation: The Windows message queuing service, which is a Windows component, needs to be enabled for a system to be exploitable by this vulnerability. This feature can be added via the Control Panel. You can check to see if there is a service running named **Message Queuing** and TCP port 1801 is listening on the machine.

**What security feature is bypassed with this vulnerability?** The RDP Gateway protocol is enforcing the usage of Datagram Transport Layer Security (DTLS) version 1.0, which is a deprecated (RFC 8996) protocol with known vulnerabilities. An attacker with a machine-in-the-middle (MitM) position who successfully exploited this vulnerability could compromise the confidentiality and integrity of data when the targeted user connects to a trusted server.

**According to the CVSS metric, a successful exploitation could lead to a scope change (S:C). What does this mean for this vulnerability?** The vulnerability is in the web server, but the malicious scripts execute in the victim’s browser on their machine.

**What security feature is being bypassed?** An attacker with a machine-in-the-middle (MitM) position who successfully exploited this vulnerability could bypass the certificate validation performed when a targeted user connects to a trusted server.

* Customers who use Microsoft Defender for Office are protected from attachments that attempt to exploit this vulnerability. * In current attack chains, the use of the Block all Office applications from creating child processes Attack Surface Reduction Rule will prevent the vulnerability from being exploited. * Organizations who cannot take advantage of these protections can set the FEATURE\_BLOCK\_CROSS\_PROTOCOL\_FILE\_NAVIGATION registry key to avoid exploitation. Please note that while these registry settings would mitigate exploitation of this issue, it could affect regular functionality for certain use cases related to these applications. Add the following application names to this registry key as values of type REG\_DWORD with data 1.: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BLOCK_CROSS_PROTOCOL_FILE_NAVIGATION * Excel.exe * Graph.exe * MSAccess.exe * MSPub.exe * PowerPoint.exe * Visio.exe * WinP...

Mitigation refers to a setting, common configuration, or general best-practice, existing in a default state, that could reduce the severity of exploitation of a vulnerability. The following mitigating factors might be helpful in your situation: The Windows message queuing service, which is a Windows component, needs to be enabled for a system to be exploitable by this vulnerability. This feature can be added via the Control Panel. You can check to see if there is a service running named **Message Queuing** and TCP port 1801 is listening on the machine.

**According to the CVSS metric, a successful exploitation could lead to a scope change (S:C). What does this mean for this vulnerability?** The vulnerability is in the web server, but the malicious scripts execute in the victim’s browser on their machine.

**What security feature is bypassed with this vulnerability?** The RDP Gateway protocol is enforcing the usage of Datagram Transport Layer Security (DTLS) version 1.0, which is a deprecated (RFC 8996) protocol with known vulnerabilities. An attacker with a machine-in-the-middle (MitM) position who successfully exploited this vulnerability could compromise the confidentiality and integrity of data when the targeted user connects to a trusted server.

**What security feature is being bypassed?** An attacker with a machine-in-the-middle (MitM) position who successfully exploited this vulnerability could bypass the certificate validation performed when a targeted user connects to a trusted server.