threat-intel New HollowGraph Malware Abuses Microsoft 365 Calendar for C&C Communication HollowGraph, a new malware dubbed by Group-IB, leverages Microsoft 365 calendars to establish command-and-control communication, specifically targeting Israeli entities. The malware uses a sophisticated technique to hide its C&C traffic within legitimate calendar events, and is linked to the Iran-nexus threat actor Lyc… SecurityWeek · Jul 21, 2026 High ILmicrosoft 365c&ccalendar
threat-intel New Project CAV3RN module abuses Outlook calendar events for C2 and DNS AAAA records for configuration recovery Kaspersky researchers have uncovered a sophisticated new module, Project CAV3RN, leveraging Outlook calendar events accessed through Microsoft Graph for C2 communication and DNS AAAA records to recover configuration data… Securelist · Jul 21, 2026 High ISc2microsoftdns
threat-intel HollowGraph Malware Hides C2 and Stolen Files in Microsoft 365 Events Dated 2050 A sophisticated espionage implant, dubbed HollowGraph, is using a hijacked Microsoft 365 calendar as its command and control channel to steal data and deliver instructions. The malware, linked to the Iranian threat group… The Hacker News · Jul 20, 2026 High ISIRespionagecommand-and-controlmicrosoft 365
