Mozla

Overview

Executive Summary

Infection Vector and Stealth Mechanisms

• 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.

Security and Privacy Implications

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:

• Trojan.Mozla
• Win32/Mozla
• Backdoor.Mozla

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:

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.

MITRE D3FEND™ Defensive Countermeasures

Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):

Tiered Detection Rules (Cisco CAIRN Model)

Modern threat detection requires multi-layered rule engineering. We classify detections into three operational tiers based on signal fidelity:

rule MALWARE_WIN_MOZLA_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Mozla"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    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
}

title: SystemHelpDesk Detection - Mozla (Trojan) Execution & Triage
id: 80cd2a53-477a-569d-a3b1-4fc98d8d99f7
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Mozla malware family. Detects suspicious execution from temporary user
  directories with hidden window flags and background transfer utilities.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/mozla
- https://malware-families-catalog.systemhelpdesk.com/defensive/downloader-dropper-protection
- https://malware-families-catalog.systemhelpdesk.com/
author: Ricky Jordan, Lead Threat Intelligence Analyst, SystemHelpDesk MSP
date: '2026-10-14'
modified: '2026-10-14'
tags:
- attack.trojan
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1036_005
- attack.t1055
- attack.t1105
- attack.t1059
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \cmd.exe
    - \powershell.exe
    - \cscript.exe
    - \wscript.exe
    CommandLine|contains:
    - AppData\Local\Temp
    - -WindowStyle Hidden
    - /e:jscript
    - bitsadmin /transfer
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: medium

rule MALWARE_WIN_MOZLA_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Mozla tradecraft"
        tier = "T3 - Attribution Fingerprint"
        confidence = "High (Confirmed Family Signature)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        // Core family identifier & heuristic payload signatures
        $attrib_str = "mozla" ascii wide nocase
        $pe_magic = "MZ" ascii
        $net_marker = "http" ascii nocase
    condition:
        uint16(0) == 0x5a4d and ($attrib_str and $net_marker) and filesize < 15MB
}

Containment & Response Steps

Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.

1. Sever network connectivity for the flagged endpoint to terminate persistent command-and-control (C2) communication channels and stop Mozla from retrieving secondary stage payloads.
2. Capture process memory triage to detect and terminate malicious threads injected by Mozla into legitimate system processes such as explorer.exe or svchost.exe.
3. Audit Windows Registry Run keys (HKCU\Software\Microsoft\Windows\CurrentVersion\Run) and Task Scheduler entries to locate and purge Mozla persistence hooks.
4. Deploy updated enterprise EDR detection signatures and conduct an out-of-band endpoint scan to isolate dropped binaries and staged payloads.
5. Rotate all credentials, domain user passwords, and session cookies active on the system during the Mozla execution timeframe.

What to Avoid

Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.

1. Do not assume the incident is resolved simply because an antivirus tool removed the initial Mozla dropper; always verify that secondary payloads and persistence hooks have been eradicated.
2. Avoid logging in with Domain Admin or privileged credentials on a machine suspected of running Mozla until memory triage is complete.
3. Do not delay host isolation; automated lateral movement and credential dumping can occur within minutes of initial execution.

References & External Analysis

• Search "mozla" on VirusTotal (External Analysis)
• Search "mozla" on Any.Run (Sandbox Sandbox)
• Search "mozla" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Cleanlog
• Erazer_Lite
• Polypatch
• Candyopen
• Hostspatcher
• Miniduke
• Bitter
• Cardtool

Machine-readable

Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/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.