Security vendors Check Point and Sublime Security have warned of a sharp escalation in attacks that use malicious calendar invites to reach targets. Sublime Security recorded a 1,216% month-over-month increase in August 2026, with the first half of September also mentioned as a period of continued activity, according to the report.
The two companies' warnings highlight calendar invites as an increasingly popular vector for attackers. The report does not detail the specific payloads or methods, but the scale of the increase suggests the approach is gaining traction.
Both Check Point and Sublime Security agree on the overall trend, though the source provides specific numbers only from Sublime. The lack of additional detail means it is unclear whether Check Point saw a similar magnitude of increase.