Fake GrubHub emails promise tenfold return on sent cryptocurrency

Grubhub merchant partners received fraudulent ‘Holiday Crypto Promotion’ emails from addresses on the legitimate b.grubhub.com subdomain promising to 10x any Bitcoin sent; messages included recipient names and were sent starting December 24. Recipients and observers suspect an email-authentication bypass (DNS takeover rumored), though Grubhub says it isolated the issue and is investigating; no evidence of malware or large-scale system compromise is presented.