The core of the approach is the users who are bypassing all the security controls, implemented in the business communication infrastructure and easily become victims. The biggest problem is not only the email data leakage, but the hijacked account, which later on can be used by the attacker to execute further attacks like Business Email compromise where this user may instruct other employees to conduct fraudulent activities unintentionally.
No matter how good logical controls and cyber security solutions you have implemented, none of them can detect and protect your organization from a “trusted” hijacked employee’s account… Unless, you fully monitor and inspect а user’s activity and compare it with already established behavior template of the particular user.
Educating employees to recognize the current cyber-attack vectors together with ensuring back up through their automated machine-learning behavior anomalies detection, forming a so-called “Human Layer Security” (https://bulpros.com/offerings/cyber-security/) could be a solution and indeed is the key to put you on the edge of the cyber security resilience.
Should you wish to furthermore straighten the security of your SharePoint spaces by real-time malware inspection, the GBS – a BULPROS company, has recently launched its IQ.Suite360 – a multi-level malware protection solution for SharePoint (https://www.gbs.com/en/iqsuite-360).