Threat Brief: Mitigating Large-Scale Credential Attacks (Updated August 18)
Unit 42 reports actor TheHatman claims large-scale theft of Microsoft Entra credentials and provides mitigation guidance for credential attacks.
Palo Alto Networks Unit 42 published an updated threat brief on mitigating large-scale credential attacks. In August 2026, the actor TheHatman claimed to have stolen a large volume of credentials from organizations' Microsoft Entra tenants. The brief outlines defensive guidance for organizations facing large-scale credential attacks. The theft claims originate from the actor and the post focuses on mitigation steps.
Suspected Russian Hackers Abuse Google OAuth and WhatsApp Linking to Hijack Accounts
Google tracked three suspected Russian espionage clusters abusing OAuth flows, app passwords, and WhatsApp linking to hijack accounts of diplomats and defense targets.
Google Threat Intelligence Group detailed three suspected Russian espionage clusters, UNC6293, UNC7005 (Storm-2945), and UNC5976, targeting academia, aerospace, defense, governments, and think tanks in Europe, the US, Ukraine, and Armenia. UNC6293, assessed as a sub-cluster of APT29/Ice Relic, conducted OAuth and application-specific password phishing while impersonating State Department officials. UNC5976 registered file-sharing-themed domains hosting fake OAuth login pages and deployed a malicious Excel plugin codenamed HEADRUSH, while UNC7005 abused WhatsApp device linking to hijack accounts and record victims' audio and video.
Impersonating IT support: how threat actors turn a remote session into enterprise-wide access
Microsoft details Teams IT-support impersonation campaigns deploying Node.js implants, AD reconnaissance, and WinRM lateral movement toward domain controllers.
Microsoft Threat Intelligence describes a human-operated campaign where attackers impersonate IT/helpdesk staff via Microsoft Teams external collaboration, talk users into granting remote sessions, and use RMM tools for interactive access. During the session they run PowerShell to silently install a malicious MSI that stages a portable Node.js runtime and obfuscated JavaScript implant for C2, executing follow-on payloads via rundll32. Operators then perform host and Active Directory reconnaissance, capture desktop screenshots, and pivot via WinRM on port 5985 to domain controllers and certificate authorities. The hands-on-keyboard chain, which can precede data theft and ransomware, blends into normal operations by relying on Teams, Quick Assist, msiexec, and Node.js; Microsoft shares hunting and mitigation guidance.
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.
UNC6671 Vishing Attacks Target Personal Phones to Steal SaaS Data
Google and Mandiant attribute vishing-based SaaS data extortion attacks to UNC6671, now operating under the Redact, Pink, Helix, and Falcon brands.
Google Threat Intelligence Group and Mandiant track extortion group UNC6671, which uses vishing calls impersonating IT help desks to lure employees to adversary-in-the-middle phishing pages that capture credentials, MFA tokens, and session tokens. The group then registers adversary-controlled MFA devices, pivots through identity providers into Microsoft 365, Okta, and other SaaS applications, and runs automated Python and PowerShell exfiltration scripts. UNC6671 has rotated through extortion brands including BlackFile, Redact, Pink, Helix, and Falcon, and Google tracked over $10.6 million in Bitcoin payments between January 7 and May 12, 2026, with initial demands exceeding $3 million. The actor has hit dozens of organizations in North America, Australia, and the UK, shifting toward high-value financial and legal firms in July 2026.
Slim Spider Steals Crypto Custody Secrets From Brazilian Financial Institution
CrowdStrike links previously unseen Slim Spider group to crypto custody secret theft at Brazilian financial institutions since March 2026.
CrowdStrike is tracking Slim Spider, a previously undocumented financially motivated group attacking Brazilian financial institutions since at least March 2026. The actor used custom Bash scripts to steal temporary cloud credentials, exfiltrated digital asset custody secrets, and used Foundry's cast tool to derive Ethereum wallet addresses, while deploying Go-based backdoor MikeDor and an implant impersonating Brazil's SPI instant payment infrastructure. Slim Spider also pivoted to Azure DevOps and Kubernetes clusters and used panels including NEXUS // Scanner, Painel de Emails Entra ID, and Painel Pix for reconnaissance and unauthorized Pix transfers. Separately, Google Threat Intelligence Group and Mandiant disclosed Breeze Comet (CL-CRI-1163), a Portuguese-speaking group since 2024 that breaches Brazilian payment infrastructure to run fraudulent Pix, Boleto, and STR transactions.