Threats Tagged 'quick assist'

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...

In April 2026, threat actors deployed Nimbus RAT against a legal industry target using Microsoft Teams voice phishing. The attack began with email bombing (282 emails in 90 minutes), followed by a fake IT helpdesk contact via Teams who convinced the victim to grant Quick Assist remote access. Within 20 minutes, a Java-based RAT was deployed that uses Google Drive and Google Sheets for command-and-control, making network traffic appear benign. Analysis of 1,540 suspicious Teams messages across 172 customer environments over 12 months revealed 65% originated from throwaway onmicrosoft.com tenants with IT-themed names. The malware bundles its own Java runtime, implements two credential theft mechanisms, and allows in-memory second-stage code execution. Post-compromise targeting included Signal Desktop attachments and Outlook mailboxes.

In February 2025, BlackBasta ransomware operations ceased after their internal chat logs were leaked online, leading to disbandment. However, former affiliates continued launching attacks using different ransomware families, including the relatively unknown Payouts King group that emerged in April 2025. ThreatLabz has observed continued ransomware activity consistent with former BlackBasta initial access brokers since early 2026, utilizing similar tactics including spam bombing, Microsoft Teams phishing, and Quick Assist abuse. Payouts King implements sophisticated evasion techniques including stack-based string obfuscation, API hashing, and direct system calls to terminate security processes. The ransomware leverages 4,096-bit RSA and 256-bit AES counter mode encryption, selectively encrypting files while targeting security software and employing anti-forensics techniques like shadow copy deletion and event log clearing.

A Microsoft Teams voice-phishing campaign leveraging Quick Assist, a remote administration tool, was tracked in September 2025. The campaign uses help desk scams to gain initial access, followed by user group enumeration and the execution of a PowerShell script to download a command and control payload. The attack employs AMSI bypass, encrypted communications, and a web-socket remote access trojan. Multiple Microsoft 365 tenants with IT-related subdomains were used, along with various IPs and domains for C2 infrastructure. The campaign shows similarities to Storm-1811 and PhantomCaptcha activities, suggesting a complex cybercrime ecosystem. The attackers' ultimate goal may be ransomware deployment, although observed attempts were successfully blocked.

MediumMalwareUnited KingdomGermanyFrance+5#netsupport manager#cybercrime#powershell

A sophisticated social engineering campaign exploits Microsoft Teams' 'Chat with Anyone' feature to impersonate IT support and trick users into initiating Quick Assist sessions. This multi-stage attack involves phishing, malware deployment (notably an infostealer named 'updater.exe'), and reconnaissance to steal credentials and potentially exfiltrate data. The threat actors leverage legitimate collaboration tools to bypass traditional security controls. Organizations are advised to disable the vulnerable Teams feature, enforce multi-factor authentication, and adopt Zero Trust principles to mitigate risks. No CVSS score is assigned, but the attack poses a medium severity risk due to its credential theft focus and social engineering complexity.

MediumCampaignGermanyFranceNetherlands+4#reconnaissance#infostealer#quick assist