Fullscreen
Overview
Adware:Win32/Fullscreen is an aggressive, highly disruptive Potentially Unwanted Program (PUA) and adware family designed to monetize an infected endpoint by forcefully injecting massive, full-screen advertisements into the user's web browser or directly onto the Windows desktop, regardless of what the user is doing.
Understanding Fullscreen Adware
To an end-user, a Fullscreen infection renders the computer nearly unusable. The adware completely hijacks the screen real estate, constantly interrupting workflows with unavoidable, full-screen pop-ups that are often difficult to close. For a security analyst, this represents a severe degradation of endpoint functionality and a significant risk of secondary infections, as these aggressive ads frequently employ malvertising to deploy actual trojans or ransomware.
Execution and Disruption Mechanics
Fullscreen is typically distributed via deceptive software bundlers (`T1189`) found on torrent sites or third-party freeware portals. Upon execution (`T1204.002`), it establishes deep persistence, often creating multiple randomized Scheduled Tasks (`T1053.005`) and Registry Run keys to ensure it survives reboots. It utilizes hidden browser extensions (`T1176`) or standalone adware processes to intercept web traffic and inject its payload. It deliberately uses Windows UI APIs (`T1562`) to force the advertisement windows to stay 'always on top' and maximize to full screen, maximizing the chance the user accidentally clicks the ad and generates affiliate revenue.
Indicators of Compromise & Impact
The primary impact is the total loss of user productivity and the high risk of secondary malvertising infections. Incident responders will observe anomalous HTTP/HTTPS traffic routing through known, aggressive adware affiliate networks. EDR logs will flag the installation of the rogue Scheduled Tasks and the constant launching of hidden browser instances or unknown executables attempting to draw full-screen UI elements.
MITRE ATT&CK Techniques
Observed techniques used by this family, mapped to the MITRE ATT&CK framework:
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_FULLSCREEN {
meta:
description = "Detects Fullscreen (ransomware)"
author = "SystemHelpdesk Boilerplate Generator"
date = "2026-07-06"
strings:
$s1 = "fullscreen" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Sigma Rule
title: Suspicious Fullscreen Activity
id: 74ba0736dad9b7236e2c7db4f4f4b874
status: experimental
description: Detects generic indicators of the fullscreen malware family.
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith:
- '\cmd.exe'
- '\powershell.exe'
CommandLine|contains:
- "*fullscreen*"
condition: selection
level: mediumContainment & Response Steps
Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.
- Use the Windows Control Panel to attempt uninstallation of the adware and any bundled software installed on the exact same date.
- Deploy an enterprise adware removal tool (e.g., AdwCleaner or Malwarebytes) to locate and strip the deeply embedded Scheduled Tasks and hidden registry hooks.
- Force a complete reset of all installed web browsers to factory defaults to eradicate rogue extensions.
- If the full-screen ads prevent interaction with the desktop, reboot the computer into Safe Mode to perform the cleanup.
What to Avoid
Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.
- Do not instruct the user to simply 'click the X' on the ads; aggressive adware often fakes the close button to register an illicit click or trigger a secondary download.
- Avoid ignoring the infection; the malvertising networks utilized by Fullscreen often rotate their payloads and may drop severe malware.
References & External Analysis
- Search "fullscreen" on VirusTotal (External Analysis)
Frequently Asked Questions
How do I remove the Fullscreen Ransomware from Windows?
Manual removal of Fullscreen 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 Fullscreen a virus or a Ransomware?
Fullscreen is classified as a Ransomware. Unlike traditional viruses that infect files, modern malware like Fullscreen typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Fullscreen infection?
Symptoms of Fullscreen 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: ransomware)
Explore other malware families in the same category:
Protect Your Network Against Ransomwares
Want to prevent Fullscreen and similar threats from compromising your organization? Read our comprehensive defensive guide: Ransomware Protection Guide.
Machine-readable
Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/api/fullscreen.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.