Tag: covert c2 channel

HollowGraph Malware Exploits Microsoft 365 Calendar for Covert C2 Channel

Meet HollowGraph, a sneaky espionage implant that hijacks Microsoft 365 calendars to secretly communicate with its operators, never even touching an attacker-controlled server. By masquerading as a harmless calendar event, HollowGraph quietly receives instructions and sends stolen data under the radar.