An email campaign asking victims to call a bogus number to suspend supposedly fraudulent subscriptions got right past Microsoft s native email controls. A pair of billing and tech support vishing attacks using Geek Squad and Norton Antivirus as cover managed to hit 25,000 mailboxes recently. The only call to action in the email was a phone number that would supposedly connect the recipient to the billing department in order to process order returns. The method enabled the emails to bypass standard threat-detection controls.
Source: https://threatpost.com/geek-squad-vishing-bypasses-email-security/167014/