Detect Suspicious Large File Transfer (Ransomware Exfiltration)
This rule detects suspicious large file transfers over the network, specifically looking for connections where more than 100MB (104857600 bytes) of data has been sent or received. It then aggregates these transfers by device and remote IP within one-hour bins and flags if five or more such large transfers occur within that hour. This behavior can be indicative of data exfiltration, often associated with ransomware attacks or other malicious data theft activities.
Microsoft Sentinel (KQL)

