Google-owned Mandiant reported an expansion in ShinyHunters-style intrusions using voice phishing (vishing) and spoofed credential-harvesting sites to steal SSO credentials and MFA codes, enabling unauthorized access to cloud SaaS environments. Mandiant tracked the activity across multiple clusters (UNC6661, UNC6671, and UNC6240 / ShinyHunters) and assessed the objective as data theft from cloud applications (including internal communications) followed by extortion, with some incidents involving escalatory pressure such as harassment of victim personnel. In observed tradecraft, operators impersonated IT staff, directed employees to phishing links under the pretext of updating MFA settings, then used captured credentials to enroll attacker-controlled devices for MFA.
Separate reporting characterized the same campaign as a broad vishing operation with hundreds of organizations in scope, reinforcing that the activity is not limited to a single SaaS provider and is focused on identity-layer compromise rather than software exploitation. Other items in the set were unrelated: a supply-chain compromise of eScan antivirus update infrastructure distributing a backdoor, a Fortinet write-up on Interlock ransomware tradecraft, an article on EU vulnerability identifier policy, and general security-awareness/detection-engineering content; these do not describe the ShinyHunters vishing activity and should not be treated as part of the same incident thread.

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On January 31, 2026, Mandiant published research describing multiple related clusters—UNC6661, UNC6671, and UNC6240/ShinyHunters—behind the campaign. It said the activity was driven by social engineering rather than vendor vulnerabilities and released hardening, logging, and detection guidance, including use of phishing-resistant MFA.
CSO Online highlighted reporting that ShinyHunters had ramped up a new vishing campaign, with hundreds of organizations or individuals in the crosshairs. The report framed the activity as a significant escalation in the scope of targeting.
In at least one case during the campaign, attackers used a compromised email account to phish contacts in the cryptocurrency sector and then deleted sent messages to reduce evidence. This reflected a further operational step beyond initial access and SaaS compromise.
During the January 2026 activity, the threat clusters used stolen credentials to enroll attacker-controlled MFA devices, move into cloud SaaS platforms, and exfiltrate sensitive data for extortion. Mandiant also noted harassment of victim personnel as part of the escalation.
Mandiant said it observed extortion-focused activity in early to mid-January 2026 using tradecraft consistent with the ShinyHunters ecosystem. Attackers impersonated IT staff in voice phishing calls and used victim-branded credential-harvesting pages to steal SSO credentials and MFA codes.
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