Mozla

Category: trojan · Aliases: Trojan.Mozla, Win32/Mozla, Backdoor.Mozla · Sample count (EMBER 2018): 1 · Enrichment: insufficient_information · Updated: 2026-07-01T16:09:08Z

Category: TrojanActor: Unknown / CybercriminalIndustry: Global / OpportunisticMotivation: Opportunistic

Overview

Executive Summary

Mozla is a highly deceptive Trojan designed to exploit user trust by masquerading as legitimate components of the Mozilla Firefox web browser. By mimicking official processes and file structures, Mozla attempts to bypass behavioral detection and user scrutiny, enabling it to establish a persistent backdoor for remote attackers.

Infection Vector and Stealth Mechanisms

Mozla is predominantly distributed through deceptive drive-by downloads or as part of a bundled software package downloaded from untrustworthy software repositories. It may also be delivered via phishing emails containing links to fake "browser update" pages. Upon execution, Mozla employs sophisticated camouflage techniques:

Process Spoofing: It injects its malicious payload into memory and names the executing process `firefox.exe` or `mozla.exe`. To the untrained eye checking the Windows Task Manager, the process appears to be a legitimate instance of the Firefox browser running in the background.
Directory Mimicry: Mozla frequently installs its binary files within the `%AppData%\Mozilla` or `%ProgramFiles%\Mozilla Firefox` directories, attempting to blend in with valid browser extensions and configuration files.

Once persistence is established (often via registry run keys), Mozla acts as a downloader and backdoor, communicating with a command-and-control (C2) server to receive instructions and download secondary payloads, such as banking trojans or info-stealers.

Security and Privacy Implications

The primary threat posed by Mozla is its ability to evade initial detection and grant an attacker persistent, remote access to the compromised host. Because it operates under the guise of a trusted application, standard endpoint firewalls may inadvertently allow its outbound C2 communications.

Remediation and Eradication

Process Verification: Utilize advanced task management tools (like Sysinternals Process Explorer) to verify the digital signature of all running `firefox.exe` instances. Legitimate Mozilla executables are signed by the Mozilla Corporation.
Endpoint Detection and Response (EDR): Configure EDR solutions to monitor for anomalous parent-child process relationships. A legitimate browser process should generally not be spawning `cmd.exe` or `powershell.exe`.
Automated Removal: Run a comprehensive scan using a reputable anti-malware platform to isolate and remove the Mozla binaries and their associated registry persistence mechanisms.

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: T1036.005 T1055 T1105 T1059

Tactical Mitigations

Based on the techniques used by this family, consider the following defensive strategies:

T1036.005: Monitor for executable files running from unusual paths or with deceptive names. Use EDR to detect process masquerading.
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.

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_MOZLA {
    meta:
        description = "Detects Mozla (trojan)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "mozla" ascii wide nocase
        $s2 = "trojan.mozla" ascii wide nocase
        $s3 = "win32/mozla" ascii wide nocase
        $s4 = "backdoor.mozla" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Mozla Activity
id: 3d8dbb3e80c4d8d565ffbfc1788ba8f8
status: experimental
description: Detects generic indicators of the mozla malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*mozla*"
            - "*trojan.mozla*"
            - "*win32/mozla*"
            - "*backdoor.mozla*"
    condition: selection
level: medium

References & External Analysis

Search "mozla" on VirusTotal (External Analysis)

Frequently Asked Questions

How do I remove the Mozla Trojan from Windows?

Manual removal of Mozla 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 Mozla a virus or a Trojan?

Mozla is classified as a Trojan. Unlike traditional viruses that infect files, modern malware like Mozla typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.

What are the main symptoms of a Mozla infection?

Symptoms of Mozla 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 Mozla and similar threats from compromising your organization? Read our comprehensive defensive guide: Banking Trojan Protection.

Need help with an active incident? Published by the SystemHelpdesk team.

Machine-readable

Get this profile as JSON: https://jordanricky1604-ship-it.github.io/malware-families-catalog/api/mozla.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.