Passkey-themed social engineering leads to identity and cloud compromise
Microsoft tracks ongoing cloud intrusions where passkey-themed helpdesk lures enable AiTM credential theft, MFA persistence, and SharePoint data theft.
Microsoft Security Research is tracking active cloud-based intrusions, observed since May 2026, that begin with helpdesk impersonation calls and SMS lures urging urgent passkey, MFA, or SSO updates. The lures lead to adversary-in-the-middle phishing or device-code authentication flows that capture credentials and session tokens or grant actor access, after which the actors add authentication methods, conduct Microsoft Graph reconnaissance, and download SharePoint and OneDrive content via REST APIs. Phishing domains embed victim organization names as subdomains (e.g., contoso.add-passkey[.]com), are often registered with Nicenic, and go operational within hours. Microsoft advises revoking sessions and removing unauthorized authentication methods for confirmed compromises.
Cavern C2 Uses DNS and Google Apps Script to Blend Into Legitimate Traffic
Kaspersky details Iranian Cavern Manticore's expanded C2 framework using DNS and Google Apps Script, plus APT42's TAMECAT spyware in nuclear-sector phishing.
Kaspersky reported new components in the Cavern (Cav3rn) C2 framework, used by Iranian MOIS-affiliated Cavern Manticore (with overlaps to MuddyWater and OilRig's Lyceum) against Israeli entities, monitored since December 2025. The new GoogleService.dll module performs DNS A-record queries to choose between direct HTTPS and a Google Apps Script relay per transaction, with the DNS infrastructure able to rotate the Google deployment ID; Kaspersky also found an inter-component broker (rnp.dll) and linked the framework's plugin-based pivot to late April 2026. Separately, Group-IB and Kaspersky detailed HOLLOWGRAPH, a .NET NativeAOT DLL first seen in the wild June 7, 2026, that uses Microsoft 365 calendar events via the Graph API as two-way dead drops dated May 13, 2050, with DNS tunneling refreshing Entra ID credentials. DarkAtlas also reported APT42's TAMECAT modular surveillance framework delivered via LNK masquerading as PDFs in spear-phishing targeting the nuclear energy sector in April-May 2026, with the group using generative AI to accelerate operations.
xHunt Campaign: Attacks on Kuwait Shipping and Transportation Organizations
xHunt deployed custom backdoors Hisoka, Killua, Gon, and EYE against Kuwait shipping and transportation organizations, using DNS tunneling and email-draft C2 channels.
Unit 42 observed the xHunt campaign targeting Kuwait transportation and shipping organizations between May and June 2019, installing backdoors named after characters from the anime Hunter x Hunter, including Hisoka, Killua, Sakabota, and Netero. The tools use HTTP and DNS tunneling for C2, and Hisoka v0.9 added an unusual email-based C2 channel that abuses Exchange Web Services with stolen credentials to exchange email drafts. The Gon tool provides port scanning, file transfer, screenshots, remote command execution, and RDP session creation, while EYE acts as a cleanup failsafe if a legitimate user logs in. Related activity targeting Kuwait between July and December 2018 was reported by IBM X-Force IRIS, suggesting the campaigns are likely related.