Favadd
Overview
Executive Summary
Favadd (often detected as Adware.Favadd or Trojan.Favadd) is a class of Adware and Potentially Unwanted Programs (PUP) prevalent during the era of heavy browser hijacking. Its primary objective is aggressive and unauthorized monetization by forcefully altering a user's web browser settings, specifically by injecting hundreds of unsolicited, sponsored bookmarks ("favorites") and changing the default homepage to redirect traffic to affiliate marketing sites or fraudulent search portals.Infection Vector and Technical Capabilities
Favadd is predominantly distributed via software bundling. Users typically encounter this threat when downloading "free" utilities, media players, or browser extensions from untrustworthy third-party download portals. Upon execution, the adware operates by directly modifying browser configurations:- Bookmark Injection: Favadd aggressively modifies the configuration files and registry keys associated with major web browsers (Internet Explorer, Firefox, older versions of Chrome). It adds dozens of bookmarks leading to online casinos, fake tech support pages, and aggressive affiliate marketing sites.
- Browser Hijacking: The malware often alters the browser's default homepage, new tab page, and default search engine provider to force the user's web traffic through a monetization gateway controlled by the adware authors.
- Persistence: To prevent the user from simply deleting the bookmarks, Favadd often utilizes a background service or a persistent browser helper object (BHO) that automatically restores the malicious bookmarks upon every system reboot or browser launch.
Threat Assessment
While Favadd is generally classified as Adware and does not typically encrypt files or steal banking credentials, it represents a significant degradation of the user experience and poses a severe privacy risk. The aggressive redirection often exposes users to secondary, far more severe malware infections via "malvertising" networks.Remediation and Eradication
- Application Removal: The first step is to identify and uninstall the core adware application via the Windows Control Panel, looking for recently installed, suspicious "free" utilities or toolbars.
- Browser Reset: Because Favadd deeply alters browser configurations, the most effective remediation is a complete reset of all installed web browsers to their factory default settings, which automatically clears malicious extensions, BHOs, and injected bookmarks.
- Anti-Malware Sweep: Run a comprehensive scan using a reputable anti-malware solution specifically tuned to detect and remove Potentially Unwanted Programs (PUPs) and lingering registry keys left behind by the adware.
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: T1185 T1176 T1546.015
Tactical Mitigations
Based on the techniques used by this family, consider the following defensive strategies:
- T1185: Enforce strong MFA and use browser isolation or hardened browsers for sensitive financial or administrative portals to defeat session hijacking.
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_FAVADD {
meta:
description = "Detects Favadd (trojan)"
author = "SystemHelpdesk Boilerplate Generator"
date = "2026-07-06"
strings:
$s1 = "favadd" ascii wide nocase
$s2 = "adware.favadd" ascii wide nocase
$s3 = "trojan.favadd" ascii wide nocase
$s4 = "pup.favadd" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Sigma Rule
title: Suspicious Favadd Activity
id: bc5365195ee825ca3e36981e92f9751f
status: experimental
description: Detects generic indicators of the favadd malware family.
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith:
- '\cmd.exe'
- '\powershell.exe'
CommandLine|contains:
- "*favadd*"
- "*adware.favadd*"
- "*trojan.favadd*"
- "*pup.favadd*"
condition: selection
level: mediumReferences & External Analysis
- Search "favadd" on VirusTotal (External Analysis)
Frequently Asked Questions
How do I remove the Favadd Trojan from Windows?
Manual removal of Favadd 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 Favadd a virus or a Trojan?
Favadd is classified as a Trojan. Unlike traditional viruses that infect files, modern malware like Favadd typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Favadd infection?
Symptoms of Favadd 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)
Explore other malware families in the same category:
Protect Your Network Against Trojans
Want to prevent Favadd 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/favadd.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.