<a href="https://www.microsoft.com/security/blog/2021/05/27/new-sophisticated-email-based-attack-from-nobelium/" rel="nofollow">https://www.microsoft.com/security/blog/2021/05/27/new-sophi...</a><p>> Microsoft Threat Intelligence Center (MSTIC) has uncovered a wide-scale malicious email campaign operated by NOBELIUM, the threat actor behind the attacks against SolarWinds, the SUNBURST backdoor, TEARDROP malware, GoldMax malware, and other related components. The campaign, initially observed and tracked by Microsoft since January 2021, evolved over a series of waves demonstrating significant experimentation. On May 25, 2021, the campaign escalated as NOBELIUM leveraged the legitimate mass-mailing service, Constant Contact, to masquerade as a US-based development organization to distribute malicious URLs to a wide variety of organizations and industry verticals.