Microsoft is alerting about a rising threat cluster dubbed Storm-0539, responsible for orchestrating gift card fraud and theft through highly sophisticated email and SMS phishing attacks against retail entities, particularly during the holiday shopping season. The attacks involve the propagation of booby-trapped links that direct victims to phishing pages capable of harvesting credentials and session tokens. Once initial access is obtained, Storm-0539 registers its own device for subsequent secondary authentication prompts, bypassing multi-factor authentication (MFA) protections and persisting in the environment using the fully compromised identity.
The modus operandi includes escalating privileges, moving laterally across the network, and accessing cloud resources to grab sensitive information, specifically targeting gift card-related services to facilitate fraud. Storm-0539 also engages in extensive reconnaissance of targeted organizations, crafting convincing phishing lures and stealing user credentials and tokens for initial access. The threat actor is described as a financially motivated group, exhibiting proficiency in cloud providers and leveraging resources from the target organization’s cloud services for post-compromise activities.
Microsoft’s warning follows its recent actions against the Vietnamese cybercriminal group Storm-1152, where the company obtained a court order to seize the infrastructure. Storm-1152 was involved in selling access to approximately 750 million fraudulent Microsoft accounts and identity verification bypass tools for other technology platforms. Additionally, Microsoft cautioned about multiple threat actors abusing OAuth applications to automate financially motivated cybercrimes, including business email compromise (BEC), phishing, large-scale spamming campaigns, and illicit cryptocurrency mining through the deployment of virtual machines.
