Security2 hOctober 20, 2026, 02:00

Calendar invite phishing surged 33,000% in five months

Sublime recorded roughly a 33,000% rise in ICS-phishing between May and September 2026, exploiting how Google Calendar and Outlook auto-add events from unknown senders. Google advises accepting invites only from known contacts, while Microsoft recommends marking such messages as phishing.

Gadgetreview

Open source

Calendar invite phishing surged 33,000% in five months

ICS-phishing grew about 33,000% from May to September 2026
Month-to-month jumps: 282% in June, 338% in July, over 1,000% later
Google Calendar can limit invites to known senders only
Avoid clicking links, scanning QR codes or calling numbers in events

#Google#Microsoft#Outlook#GoogleCalendar

Fake calendar invites steal Microsoft 365 credentials in mass phishing campaign

Software

Google Calendar now shows up to three time zones with custom labels

Security

Calendar phishing is growing exponentially as fake meetings steal logins

Security

Calendar invite phishing surged 33,000% in five months

Fake calendar invites steal Microsoft 365 credentials in mass phishing campaign

Google Calendar now shows up to three time zones with custom labels

Calendar phishing is growing exponentially as fake meetings steal logins

Calendar-based phishing jumps 33,000% since May, researchers say