CVE-2021-26855 - Exchange Server Side Request Forgery Exploit - HTTP (REQUEST) - Variant 2
This is Trend Micro detection for HTTP network protocol that manifests exploit activities and can be used for Point of Entry or Lateral Movement.
The host exhibiting this type of network behavior is likely compromised by malware, or being used by a malicious insider to gain unauthorized access to other hosts in the network.
Attack Phase: Point of Entry or Lateral Movement
Risk Type: OTHERS
(Note: OTHERS can be network connections related to hacking attempts, exploits, connections done by grayware, or suspicious traffic.)
Threat Type: Exploit
Confidence Level: High
Severity: Low(Inbound)| Medium(Outbound)
DDI Default Rule Status: Disable
Event Class: Exploit
Event Sub Class: Application
Behavior Indicator: Exploit
APT Related: YES
CVE Exploit: CVE-2021-26855
To prevent future exploits, ensure that the host and others visible to the external network have their browsers, plugins, and operating systems fully updated with the latest patches. Also, use virtual patching even if the needed patch is still not available for deployment.