The strongest ''must-be-true'' confirmation for an active attack in this scenario is evidence of command-and-control (C2) or other suspicious external communication. You already have a scheduled task launching PowerShell and attempting to connect to an unknown IP address, which is a high-signal indicator of malicious automation. The fastest way to validate ongoing activity is to analyze network telemetry (firewall/proxy logs, netflow, EDR network events) to confirm whether outbound connections are occurring, how frequently, and whether data is being transferred. Network logs can reveal destination IP/port, protocols, connection success/failure, volume, and timing correlation with the scheduled task triggers. File integrity checks and system logs are useful for understanding persistence and modifications, but they may lag behind or miss short-lived network beacons. User access logs help attribute activity but do not directly confirm an active external control channel. From a SOC triage and containment perspective, confirming external connections enables immediate actions such as blocking the destination, isolating the host, and scoping for other systems contacting the same IPs/domains. Therefore, network log analysis is the most direct next step to confirm active malicious behavior.