Yuri
Overview
Executive Summary
Yuri is a highly dangerous Remote Access Trojan (RAT) and Backdoor. Its primary objective is to silently infiltrate a Windows workstation or server, establish an encrypted command-and-control (C2) channel, and grant a remote attacker full, interactive, administrative control over the compromised endpoint, effectively bypassing all local security controls.Infection Vector and Technical Capabilities
Yuri is typically deployed via highly targeted spear-phishing campaigns (often utilizing malicious macros in Office documents), drive-by downloads from compromised websites, or installed directly by an attacker who has gained initial access via compromised RDP credentials. Once executed, Yuri provides a comprehensive suite of espionage and control features:- Interactive Shell Access: The RAT provides the attacker with a hidden, interactive command-line interface (reverse shell). The attacker can execute arbitrary system commands, manipulate the registry, and manage running processes as if they were sitting at the keyboard.
- Surveillance and Espionage: Yuri typically includes modules for live audio/video capture (hijacking the webcam and microphone), capturing desktop screenshots, and a built-in keylogger to steal passwords and monitor user activity in real-time.
- Lateral Movement Platform: A compromised machine running a RAT acts as a perfect beachhead for lateral movement. The attacker can utilize Yuri's file management capabilities to upload port scanners, credential dumping tools (like Mimikatz), and additional exploits to attack other servers within the corporate network.
Threat Assessment
A Yuri infection is a critical "glass break" security incident. The presence of a functional RAT indicates that an attacker has complete sovereignty over the endpoint. Confidentiality, Integrity, and Availability of the data on that machine (and potentially the entire network) are entirely compromised.Incident Response and Remediation
- Immediate Network Isolation: Severing the C2 connection is the absolute highest priority. Disconnect the infected machine from the network immediately to cut off the attacker's interactive access.
- Hunt for Lateral Movement: Assume the attacker has already used the RAT to pivot. Incident responders must analyze network traffic logs (NetFlow, firewall logs) originating from the infected IP address to identify other potentially compromised internal hosts.
- Bare-Metal Re-imaging: Due to the extensive, interactive control a RAT provides, it is impossible to guarantee that a system has been "cleaned" manually. The attacker likely installed secondary backdoors. The only secure remediation is a complete bare-metal wipe and re-image from a trusted backup.
Known aliases
Threat reports may refer to this family under multiple names:
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1059 T1105 T1056.001 T1125
Tactical Mitigations
Based on the techniques used by this family, consider the following defensive strategies:
- T1056.001: Implement Endpoint Detection and Response (EDR) to monitor for suspicious API calls related to keystroke interception. Enforce Multi-Factor Authentication (MFA) to render stolen passwords useless.
- T1059: Restrict execution of scripting languages such as PowerShell, VBScript, or Python to authorized administrators. Enforce Script Block Logging.
- T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.
- T1125: Restrict access to local camera or microphone APIs. Utilize endpoint protection that monitors hardware access.
Generated Detections (Boilerplate)
These YARA and Sigma rules are auto-generated based on the family name and aliases. They must be heavily tuned before deployment in a production environment.
YARA Rule
rule MALWARE_WIN_YURI {
meta:
description = "Detects Yuri (trojan)"
author = "SystemHelpdesk Boilerplate Generator"
date = "2026-07-06"
strings:
$s1 = "yuri" ascii wide nocase
$s2 = "backdoor.yuri" ascii wide nocase
$s3 = "rat.yuri" ascii wide nocase
$s4 = "win32/yuri" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Sigma Rule
title: Suspicious Yuri Activity
id: 9491876179d7a80bb5c86f15dbe31422
status: experimental
description: Detects generic indicators of the yuri malware family.
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith:
- '\cmd.exe'
- '\powershell.exe'
CommandLine|contains:
- "*yuri*"
- "*backdoor.yuri*"
- "*rat.yuri*"
- "*win32/yuri*"
condition: selection
level: mediumReferences & External Analysis
- Search "yuri" on VirusTotal (External Analysis)
Frequently Asked Questions
How do I remove the Yuri Trojan from Windows?
Manual removal of Yuri is highly discouraged as it may leave persistence mechanisms intact. We recommend disconnecting the device from the internet and utilizing a professional incident response service or enterprise-grade EDR software to conduct a full forensic sweep.
Is Yuri a virus or a Trojan?
Yuri is classified as a Trojan. Unlike traditional viruses that infect files, modern malware like Yuri typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Yuri infection?
Symptoms of Yuri can include unexpected system slowness, unauthorized outbound network traffic to unknown IP addresses, disabled security software, and suspicious background processes running from AppData or Temp directories.
Related Families (Category: trojan)
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Protect Your Network Against Trojans
Want to prevent Yuri and similar threats from compromising your organization? Read our comprehensive defensive guide: Banking Trojan Protection.
Machine-readable
Get this profile as JSON: https://jordanricky1604-ship-it.github.io/malware-families-catalog/api/yuri.json
Ecosystem & Interactive Environments
This profile is part of the Malware Families Catalog, a public dataset of 2,899 malware families. The catalog is also published across our ecosystem: Hugging Face, Kaggle, Zenodo, Replit, StackBlitz, CodeSandbox, and CodePen.