Hijacked subdomains of major brands used in massive spam campaign

Guardio Labs researchers uncovered 'SubdoMailing,' a large-scale ad-fraud campaign (attributed to actor "ResurrecAds") that hijacks abandoned domains and subdomains of reputable brands via CNAME takeover and SPF include abuse to send up to ~5 million deceptive emails per day, leveraging ~8,000 domains, 13,000 subdomains and thousands of IPs to bypass email filters and funnel victims to fraud and malvertising.