Additionally, COLDRIVER has employed email marketing services like HubSpot and MailerLite to initiate campaigns, serving as the starting point for a redirection chain leading to the credential harvesting page hosted on the Evilginx server. The threat actor has further utilized a domain name service (DNS) provider to obscure the IP addresses of its actor-controlled infrastructure. COLDRIVER has been sending password-protected PDF lures to evade email security measures and has hosted files on Proton Drive. Notably, the group has upgraded its domain generation algorithm (DGA) to include a more randomized list of words when naming domains, indicating its efforts to stay ahead of detection mechanisms.
Despite these changes, COLDRIVER’s primary focus remains on email credential theft, primarily targeting cloud-based email providers hosting both organizational and personal email accounts. The Microsoft Threat Intelligence team’s observations provide insights into the evolving tactics and techniques employed by this threat actor, emphasizing the importance of vigilance and enhanced cybersecurity measures to counter such advanced adversaries.