Threats Tagged 'initial access broker'

Since January 2026, a threat actor likely functioning as an initial access broker for ransomware operations has been targeting organizations through Microsoft Teams vishing attacks. Attackers impersonate IT helpdesk staff to convince victims to initiate Quick Assist remote sessions. Following initial compromise, PowerShell scripts deploy a Go-based backdoor called GoGRPC, which exists in four distinct variants: Lep, Giver, Pet, and Kind. These variants communicate with command-and-control infrastructure using gRPC over HTTP/2, an uncommon approach that helps blend malicious traffic with legitimate communications. Additional tools observed include BlindDoor backdoor, RevSocket and PyGRPC SOCKS proxies, S3Siphon data exfiltration utility, and RSOX Rust-based proxy relay. Recent campaigns show increased sophistication and selectivity, with heightened focus on corporate environments through enhanced PowerShell scripts capable of antivirus detection, domain controller fingerprinting, and system reconnaissance b...

Between January and June 2026, multiple unrelated organizations experienced nearly identical intrusions following a standardized seven-step attack chain. The attacks exploited CitrixBleed 2 (CVE-2025-5777), a memory-overread vulnerability in NetScaler ADC and Gateway appliances. Attackers sent malformed pre-authentication login requests that leaked NetScaler memory containing valid session tokens, bypassing multi-factor authentication by hijacking active sessions. Following initial access, threat actors consistently escalated privileges to SYSTEM using a registry-symlink exploitation technique targeting the AppMgmt service, created rogue administrator accounts (CtxAppVCOMService, ctxsvc, test), and established persistence through legitimate remote access tools including ScreenConnect and Zoho Assist. The most advanced case culminated in DragonForce ransomware deployment. The highly standardized tradecraft, reused infrastructure, and consistent indicators across unrelated victims suggest a single Initial Ac...