How to avoid installation of the Casbaneiro trojan

What is Casbaneiro?

Casbaneiro (also known as Metamorfo) is malicious software that is categorized as a trojan. This particular trojan targets banks and cryptocurrency services. In summary, cyber criminals use this malware to steal sensitive, confidential information that can be misused to generate revenue in various ways.

This trojan is capable of operating as a remote access tool (RAT) and can perform various tasks on infected computers.

Casbaneiro can be used to take screenshots, record keystrokes, download and execute files (executables), and prevent victims from accessing various websites. It can also update itself by downloading and installing necessary updates.

Through taking screenshots remotely, cyber criminals are able to capture information entered in sensitive documents that victims open, and other private details. The keystroke logging feature allows them to record keys pressed, and therefore they can steal logins, passwords, and other personal information entered via the keyboard.

They can also use this feature to steal various accounts. For example, emails, social networking, banking, and others. This information is used for a number of purposes such as proliferating malware, making fraudulent purchases, transactions, etc. Casbaneiro might also be used to download and execute malicious files.

Therefore, cyber criminals can install additional malware including ransomware, cryptocurrency miners, and other unwanted software. People with computers infected with Casbaneiro will be unable to access certain websites, since this malware is capable of restricting access.

Furthermore, it can collect details about the system such as operating system version, list of installed antivirus software, computer name, and username. It can check whether Trusteer, Diebold Warsaw GAS Tecnologia, and various banking applications are installed on the operating system.

This trojan can replace the cryptocurrency wallet address that is saved to the clipboard with another owned by the cyber criminals who control Casbaneiro through a C&C server. Casbaneiro might be used to trick people into providing their Outlook account credentials.

It can also install malware that, if executed, will display a fake pop-up window stating that there is a problem with Outlook and asking victims to enter their credentials through a fake Microsoft login window/page. Casbaneiro is a powerful tool that can be used to steal a wide range of information.

To avoid monetary and/or data loss, identity theft, problems with privacy, installation of other malware, and other serious issues, remove this trojan immediately.

More examples of trojan-type programs are Glupteba, Nymeria, and Retefe. Unfortunately, these are many others online. These programs often proliferate other malicious programs to infect computers with additional malware, however, the backdoor capabilities of Casbaneiro allow this trojan to do more.

If your computer is infected with a trojan or other malicious software, remove it immediately.

How did Casbaneiro infiltrate my computer?

Research shows that cyber criminals distribute Casbaneiro using malicious executables that are disguised as files that supposedly install or update legitimate apps such as Spotify, OneDrive, and WhatsApp. They might also be distributing this trojan using the names of other legitimate apps.

When these executables are launched, they begin the installation process of the Casbaneiro trojan. Cyber criminals disguise Casbaneiro's installer as the updater of financial software. They also distribute this trojan through third party Windows activators, which supposedly activate operating systems free of charge. The activator is installed, but together with the Casbaneiro trojan.

How to avoid installation of malware

Attachments in irrelevant emails that are received from unknown, suspicious addresses should not be opened. The same applies to website links. Software must be downloaded from official websites and using direct download links.

Channels/tools such as Peer-to-Peer networks (torrent clients, eMule, etc.), unofficial pages, third party downloaders, installers and other similar download or installation channels are often used to distribute trojans, ransomware, and other malware.

Installed software should be updated through tools or implemented functions that are provided by official software developers, and not third party updaters. If installed software or operating systems are licensed and require payment, they should not be activated through unofficial, third party updaters.

It is illegal to use these and they often cause installation of malicious programs. Regularly scan operating systems with reputable anti-virus or anti-spyware software and ensure that it is up-to-date. Remove any detected threats immediately.

If you believe that your computer is already infected, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate infiltrated malware.

Casbaneiro displays a fake pop-up window which opens a fake Microsoft web page designed to steal victims' credentials:

Portuguese text in this pop-up:

Prezado Cliente,
Detectamos um probnlema em sua conta Outlook.
Verifique sua conta e evite o bloqueio permanente!

Appearance of the opened web page:

Malicious process of a fake Outlook window running in Task Manager as "Project1":

Update January 22, 2020 - Cyber criminals have recently started spreading Casbaneiro (Metamorfo) malware via various email spam campaigns. The emails are presented as various notices regarding payments, business documents, etc. The sample we analyzed contained a download "button" of a document that relating to some sort of service.

Yet the download button actually lead to a .msi file which eventually injected Casbaneiro (Metamorfo) into the system.

Example of an email spam campaign used to spread this malware:

Text presented within this email:

Subject: Nota emitida 00328508620230

Nota eletronica de emitida pelo prestador serviços:
NFe : 00328508620230
Razão Social : 00328508620230 Constru MEI
CCM : 9786
Segue a baixo:

Update June 10, 2020 - Cyber criminals have recently started distributing Casbaneiro trojan by disguising it as a Kaspersky security software update. The fake updater itself is promoted via various YouTube videos which deliver download links in the video description.

Update June 18, 2020 - Casbaneiro has been recently implemented with a feature DLL-hijacking feature, which allows it to infiltrate legitimate applications and elevate the privileges, as well as ensure its persistence.

Additionally, it has been observed downloading new/additional files, which indicates that it is very likely to be updated again and will be implemented with new features.

Yet another spam email used to spread Casbaneiro malware (the download button leads to a .zip archive with malicious executable within):

Text presented within:

Estimado Cliente

Factura para el pago:

Para descargar todos los archivos zip clic Aquí: Descargar ahora Factura [RANDOMN-1/1

Favor de no responder a este correo, debido a que la cuenta no está habilitada para recibir respusta

Gracias por su preferencia.

Update March 4, 2021 - New proliferation campaign has been detected in Mexico. This operation spreads the Casbaneiro trojan through fake banking and accounting/administrative software endorsing websites. The sites themselves are promoted through tax-related email spam campaigns.

Malicious website used to promote the Casbaneiro trojan:

How to remove malware manually?

Most trojan infections can be removed by running a full system scan with Combo Cleaner. The full manual procedure below is for cases where automatic removal failed, where you want to verify a scan caught everything, or where the threat has multiple persistence points.

Tools you'll need

Combo Cleaner Antivirus 7-days free trial

Recommended primary scanner. VB100 certified. The 7-day free trial is available.

Microsoft Defender Offline Free · built-in

Built into Windows. Boots to a clean environment to catch rootkits.

Process Explorer Free

From Microsoft Sysinternals. Better than Task Manager - shows full paths and signatures.

Autoruns Free

From Microsoft Sysinternals. Lists every place malware can persist on your system.

Microsoft Safety Scanner (MSERT) Free

Official Microsoft on-demand scanner. Always-current signatures - expires every 10 days.

Phase 1~ 5 min

Contain - limit the damage

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1

Disconnect from the network

30 secNo tool needed

Unplug your Ethernet cable and turn off Wi-Fi. If you're on a laptop, the airplane-mode key works fastest.

Why this matters

Many trojans exfiltrate data - saved browser passwords, banking sessions, screenshots - and accept remote commands. Cutting the network stops both immediately. Keep it disconnected until Phase 4.

2

Boot into Safe Mode with Networking

3 min

Safe Mode loads a minimal set of drivers and stops most malware from auto-running. "With Networking" lets you download tools - re-enable Wi-Fi only after you've booted in.

Windows 11

Open Settings → System → Recovery. Click Restart now next to Advanced startup.

Your computer will restart into the "Choose an option" menu. Click Troubleshoot → Advanced options → Startup Settings → Restart. After the second reboot, press 5 or F5.

Windows 10

Click the Windows logo, hold Shift, click the Power icon and choose Restart. In the Choose an option screen, click Troubleshoot → Advanced options → Startup Settings → Restart. Press F5.

Windows 8

Go to the Start Screen, type Advanced, select Settings → Advanced startup options → Restart now → Troubleshoot → Advanced options → Startup settings → Restart → F5.

Note: Windows 8 reached end-of-life in January 2023 - running on it puts you at much higher risk of reinfection.

Windows 7

Click Start → Shut Down → Restart → OK. As the system boots, press F8 repeatedly until the Windows Advanced Options menu appears, then choose Safe Mode with Networking.

Note: Windows 7 reached end-of-life in January 2020 - running on it puts you at much higher risk of reinfection.

Phase 2~ 15 min

Identify - find what's hiding

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3

Inspect running processes with Process Explorer

Tool: Process Explorer5 min

Download Process Explorer from Microsoft Sysinternals. Run it as Administrator. Click Options → Verify Image Signatures and View → Lower Pane View → DLLs.

Sort by "Verified Signer." Anything unsigned running from %AppData%, %LocalAppData%, %Temp%, or %ProgramData% is suspicious. Right-click → Properties to see the full image path. Right-click → "Search Online" to look up unfamiliar process names.

Why not just Task Manager

Task Manager hides full file paths, doesn't show digital signatures, and groups processes in ways that make malware easy to miss. Process Explorer is the same tool Microsoft engineers use.

4

Map every persistence point with Autoruns

Tool: Autoruns 14.x10 min

Download Autoruns. Right-click Autoruns.exe and choose Run as administrator - without elevation, Autoruns can't inspect protected registry hives.

In the menu, open Options → Hide Microsoft Entries and Options → Hide Empty Locations, then click Refresh.

Modern trojans don't just live in startup. Walk through these tabs and look for unsigned or unfamiliar entries:

• Logon - classic Run/RunOnce keys
• Scheduled Tasks - frequent hiding spot, especially tasks with PowerShell, MSHTA, or rundll32 actions
• Services - unsigned services in non-Microsoft folders
• WMI - Event Subscriptions are a stealthy persistence mechanism (MITRE T1546.003)
• Image Hijacks - Image File Execution Options "Debugger" abuse
• AppInit - DLLs loaded into every GUI process
• Browser plug-ins - unsigned add-ons across all installed browsers

Pro tip

Right-click any suspicious entry → "Jump to Image" to see the actual file. Right-click → "Search Online" opens VirusTotal for the file hash. Don't delete yet - just write down the file paths and entry names. We'll remove them after the scans.

5

Check the hosts file and DNS settings

3 minBuilt into Windows

Trojans often redirect bank, antivirus, and update domains to attacker-controlled servers by editing the hosts file or DNS settings.

Hosts file: Open Notepad as Administrator and open C:\Windows\System32\drivers\etc\hosts. Legitimate entries are commented with #. Any uncommented IP-to-domain mapping is suspicious - especially redirects for microsoft.com, windowsupdate, or your bank.

DNS settings: Open Command Prompt as Administrator and run ipconfig /all. Confirm your DNS servers point to your ISP, your router, or a known public resolver (Cloudflare 1.1.1.1, Google 8.8.8.8). Then open Settings → Network & internet → [your adapter] → DNS server assignment and verify both DNS and DNS over HTTPS (DoH) settings haven't been hijacked.

Why this matters

A clean PC with hijacked DNS is still a compromised PC. You'll think you're at chase.com and you'll be at the attacker's clone.

Phase 3~ 60-90 min

Remove - three scans, one cleanup

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No single antivirus catches everything. The order below is intentional: offline scan first (catches rootkits before Windows fully loads), then on-demand scanners on the running system, then manual cleanup of anything they missed.

6

Run Microsoft Defender Offline

Tool: Built into Windows15 min

Reboot to normal Windows. Open Windows Security → Virus & threat protection → Scan options. Select Microsoft Defender Antivirus (offline scan) and click Scan now. Your computer will restart into a stripped-down environment and scan before the full operating system loads.

Why this comes first

Rootkits and bootkits hide from any scanner running on the same Windows session that's already infected. A pre-boot offline scan sees the disk before the malware can hide itself.

Recommended antivirus

Combo Cleaner

VB100 certified. Includes anti-trojan, registry/persistence scanning, anti-spyware in one pass. The 7-day free trial is available.

Download Combo Cleaner

7

Run Combo Cleaner full system scan

Tool: Combo Cleaner20-40 min

Install Combo Cleaner and run a full system scan (not the quick scan). Let it complete fully, review the detected threats, and apply the recommended actions. Combo Cleaner will quarantine known trojans and registry persistence.

8

Run Microsoft Safety Scanner as a second-opinion scan

Tool: Microsoft Safety Scanner15 min

Download Microsoft Safety Scanner (MSERT.exe), Microsoft's free on-demand tool. The binary expires every 10 days, which means every download has the latest signatures. Run a full scan after Combo Cleaner to catch anything one engine alone might miss.

Why a second scan

Different scanning engines catch different threats. Running an additional Microsoft scan after Combo Cleaner is the single most underused verification step in malware removal.

9

Manually remove anything still listed in Autoruns

Tool: Autoruns10 min

Reopen Autoruns. Anything you flagged in Step 4 that's still present hasn't been caught by the automated scans. For each remaining suspicious entry: right-click → Delete in Autoruns (this removes the persistence registration), then navigate to the file path and delete the actual file. Empty the Recycle Bin.

Important

Some malware files reappear after deletion because something else on the system recreates them. If you delete a file and it returns within minutes, you have a remaining persistence point that Autoruns didn't show - usually a service or scheduled task running under SYSTEM. Re-run the scans from Steps 6-8 or proceed to a clean install (see end of guide).

Phase 4~ 15 min

Recover - restore browsers and security

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10

Reset browsers and clear notification permissions

5 min

Trojans and adware frequently hijack browsers - change the default search engine, install rogue extensions, or grant themselves notification permissions to keep displaying scam pop-ups even after the malware is gone.

• Chrome: visit chrome://settings/reset and click "Restore settings to their original defaults." Then visit chrome://settings/content/notifications and remove any unfamiliar sites.
• Edge: visit edge://settings/reset. Then check edge://settings/content/notifications.
• Firefox: open about:support and click Refresh Firefox (Firefox uses "Refresh," not "Reset"). Then check Settings → Privacy & Security → Permissions → Notifications.

Review installed extensions in each browser and remove anything you don't recognize, especially extensions you didn't install yourself.

11

Re-enable Defender, Tamper Protection, and update everything

10 min

Many trojans disable security software. Open Windows Security → Virus & threat protection → Manage settings and confirm Real-time protection, Cloud-delivered protection, and Tamper Protection are all turned on. Tamper Protection prevents malware from disabling Defender silently.

Then run Windows Update (Settings → Windows Update → Check for updates) and update your browsers and applications. The infection vector that let the trojan in originally usually involves outdated software.

Phase 5~ 15 min + 7 days

Verify & secure

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12

Change passwords from a clean device

20 min⚠ Critical

If the trojan was an info-stealer (Lumma, RedLine, Vidar, and similar are extremely common), assume every password saved in your browser is compromised. Change them from a different, known-clean device - your phone is fine if it's not infected.

Recommended order:

1. Primary email first - it's the recovery hub for everything else
2. Banking and financial accounts
3. Password manager master password (if you use one)
4. Social media, shopping, and remaining accounts

Where available, enable phishing-resistant multi-factor authentication (passkeys / FIDO2 hardware keys / authenticator apps) - SMS-based MFA is bypassable by sophisticated attackers.

13

Verify the clean and monitor for 7 days

5 min + 1 week monitoring

Reconnect to the network and run one final full scan with Combo Cleaner. Open Task Manager (Ctrl + Shift + Esc) and switch to the Startup apps tab - confirm nothing suspicious has reappeared.

Over the next 7 days, watch for symptom recurrence: unexpected high CPU usage, unknown processes returning, browser redirects, or pop-ups. If anything returns, you missed a persistence point and the procedure needs to be repeated - or you may have a deeper compromise that requires a clean install.

When to clean install Windows instead

Manual removal isn't always the right answer. Reinstalling Windows from scratch is the only way to be 100% certain when:

• The malware reappears after every removal attempt
• A bootkit or UEFI rootkit was detected (this class of threat sits below the operating system and survives a normal Windows reinstall)
• A confirmed credential-theft trojan ran with administrator privileges (Lumma, RedLine, Vidar) - the system likely has multiple unknown payloads
• The PC is used for online banking, business email, or anything where partial doubt isn't acceptable

A clean install is a 30-60 minute process: Windows 11 reinstall via Settings → System → Recovery → Reset this PC → Remove everything → Cloud download. Back up documents to external storage first, scan the backup with Combo Cleaner before restoring it, and reinstall applications fresh - never restore them from a backup of the infected system.

Important: Manual removal requires advanced computer skills. If you're not confident identifying system files from malicious files, run an automated scan with Combo Cleaner and Windows Defender and stop there - that path catches the vast majority of consumer trojans without the risk of breaking Windows by deleting the wrong file.