data exfiltration is the unauthorized transfer of data from an organization's network to an external destination, usually for malicious purposes such as espionage, sabotage, or theft. The details given in the question suggest that data exfiltration is occurring from an endpoint device. The bursts of network utilization every seven days indicate periodic data transfers. The content being transferred appears to be encrypted or obfuscated to avoid detection or analysis. The persistent outbound TCP connection from the host to infrastructure in a third-party cloud indicates a possible command and control channel for an attacker. The HDD utilization on the device grows by 10GB to 12GB over the course of every seven days, and single file sizes are 10GB, indicating that large amounts of data are being collected and compressed before being exfiltrated.