Stopping a K-12 cyberattack (SolarMarker) with ThreatDown MDR

ThreatDown MDR discovered a long-dwelling SolarMarker backdoor in a large K-12 school district (present since at least 2021) that used obfuscated PowerShell and encoded payloads in AppData to execute and likely exfiltrate data to a suspicious IP (188.241.83.61); EDR was disabled so analysts used manual ARS/WMIC/netstat workflows to identify, terminate, and remove the payloads and confirm remediation.