Researchers Uncover HOLLOWGRAPH: Malware That Hides Inside Microsoft 365 Calendar Invites

A previously undocumented strain of Windows malware is using Microsoft 365 calendar invites as a covert communications channel, allowing attackers to issue commands and exfiltrate stolen files from victim networks while hiding in plain sight among ordinary enterprise traffic, according to new research from the threat intelligence firm Group-IB. The malware, dubbed HOLLOWGRAPH, was detailed by Group-IB ‘s Threat Intelligence team, which said it has attributed the tool with high confidence to the