2345Cn
Overview
Executive Summary
2345cn (often associated with the 2345 Explorer or Hao123 suite) is a highly aggressive Chinese-origin Browser Hijacker and Adware family. While sometimes bundled as legitimate "browser optimization" or portal software in East Asian markets, its behavior in Western environments is explicitly malicious. It forcibly takes over all installed web browsers, rendering them nearly unusable for standard navigation in order to drive traffic to 2345.com and its affiliates.Distribution and Technical Behavior
2345cn is primarily distributed via aggressive software bundling in "grey market" software installers or localized freeware downloads. Once installed, 2345cn employs extreme persistence mechanisms to lock the browser configuration:- Deep Browser Hijacking: The adware forcibly changes the homepage, default search engine, and new tab behavior to `2345.com` across Chrome, Firefox, Edge, and IE.
- Shortcut Poisoning: To prevent users from changing their homepage back, 2345cn alters all browser `.lnk` shortcut files on the Desktop, Start Menu, and Taskbar, appending the `2345.com` URL as a mandatory launch parameter (e.g., `chrome.exe http://2345.com`).
- Registry and Policy Lockdown: The malware often deploys Windows Group Policy Objects (GPOs) and deeply nested Registry keys to lock the browser settings, preventing the end-user (even those with administrative privileges) from reverting the changes via standard UI menus.
Risk Assessment
A 2345cn infection results in a severe loss of user productivity and a total compromise of browser privacy. Because it intercepts all web traffic and operates with elevated persistence, it can also act as a vector for secondary malware infections if the affiliate networks it utilizes begin serving malvertising.Incident Response and Remediation
- Shortcut Remediation: Manually inspect the `Properties -> Target` field of all browser shortcuts and remove the appended 2345 URLs.
- Registry and GPO Sweep: Anti-malware tools must be used to locate and delete the specific Registry keys and unauthorized Group Policies established by the adware.
- Browser Reset: A complete, factory reset of all installed browsers is required after the core executables and persistence mechanisms have been removed.
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: T1566.002 T1547.009 T1112 T1176
Tactical Mitigations
Based on the techniques used by this family, consider the following defensive strategies:
- T1566.002: Inspect email links for known malicious domains and use link-rewriting services for time-of-click analysis.
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_2345CN {
meta:
description = "Detects 2345Cn (advanced_threat)"
author = "SystemHelpdesk Boilerplate Generator"
date = "2026-07-06"
strings:
$s1 = "2345cn" ascii wide nocase
$s2 = "browsermodifier:win32/2345cn" ascii wide nocase
$s3 = "adware.2345" ascii wide nocase
$s4 = "pup.hao123" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Sigma Rule
title: Suspicious 2345Cn Activity
id: d8a0460c76f6e41356133055950cd8b3
status: experimental
description: Detects generic indicators of the 2345cn malware family.
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith:
- '\cmd.exe'
- '\powershell.exe'
CommandLine|contains:
- "*2345cn*"
- "*browsermodifier:win32/2345cn*"
- "*adware.2345*"
- "*pup.hao123*"
condition: selection
level: mediumReferences & External Analysis
- Search "2345cn" on VirusTotal (External Analysis)
Frequently Asked Questions
How do I remove the 2345Cn Advanced_Threat from Windows?
Manual removal of 2345Cn 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 2345Cn a virus or a Advanced_Threat?
2345Cn is classified as a Advanced_Threat. Unlike traditional viruses that infect files, modern malware like 2345Cn typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a 2345Cn infection?
Symptoms of 2345Cn 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: advanced_threat)
Explore other malware families in the same category:
Protect Your Network Against Advanced_Threats
Want to prevent 2345Cn and similar threats from compromising your organization? Read our comprehensive defensive guide: Suspect an Infection? What to do.
Machine-readable
Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/api/2345cn.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.