Discover how the HollowGraph malware exploits Microsoft 365 calendars for C2 communication and data exfiltration in targeted espionage attacks. #HollowGraph #Microsoft365 #Malware #CyberEspionage #InfoSec #GroupIB https://meterpreter.org/hollowgraph-microsoft-365-malware/?utm_source=mastodon&utm_medium=jetpack_social