EKZ Stealer Removal Guide: Browser Data Theft and FortiClient EMS Response

A file named like an endpoint patch appears around a VPN connection. On a managed work computer, that can look like another background update.

The filename alone doesn’t tell you who supplied it. When a security alert mentions EKZ, both the computer and the management route deserve attention.

Overview

EKZ is a browser-data stealer, not a legitimate patch

EKZ Stealer is Windows malware designed to collect browser credentials and other stored information. Its cleanup must be paired with protection of potentially exposed accounts.

Arctic Wolf documented a campaign involving compromised FortiClient EMS management and a payload called FortiEndpoint_Patch.exe. The legitimate Fortinet product was being abused as a delivery route.

Having FortiClient installed does not mean you have EKZ. A deployment history, security detection, and the actual management environment are needed to assess an individual device.

The campaign and the stealer perform different jobs

The primary analysis describes EKZ exporting collected browser data to a local file. Surrounding script activity then handles sending that output away.

That distinction matters during investigation. Looking only for a network connection from the stealer executable could miss activity performed by another component.

It also explains why deleting one suspicious file is not a complete response. The source of deployment and any associated scripts require review.

Contain the exposure without dismantling legitimate management

• Notify the organization responsible for the affected endpoint.
• Preserve detection details and the relevant VPN timeline.
• Have administrators inspect the management configuration and affected devices.
• Recover exposed browser accounts from a trustworthy device.

The image is a fictional file-details illustration, not an actual Windows property sheet or scan result. It highlights the reported filename without authenticating a particular file.

Why a Managed Update Can Be the Wrong Place to Put Your Trust

People are often told to avoid unfamiliar downloads. This campaign is a reminder that the delivery system can matter as much as the download’s appearance.

On an employer’s computer, software may arrive through tools controlled by administrators. The employee may not see the same installation choices as a home user.

If that management route is abused, the absence of a suspicious email does not rule out an incident. Investigators need to trace the actual deployment.

Nor should the employee assume a legitimate client application has become inherently malicious. A real tool can carry instructions that an unauthorized party inserted elsewhere.

The practical response is coordinated. The endpoint owner and management administrator each hold information the other may not see.

A user can report the moment a warning appeared. An administrator can examine policy changes, deployment records, and whether other managed computers encountered related activity.

Neither should decide the scope from the filename alone. A malicious file can use a reassuring name, and an unrelated file can share a similar label.

Preserve exact detection names, file locations, and timestamps privately. Those details help a technician compare an alert with the documented campaign.

Don’t repeatedly reconnect to the VPN to see whether the behavior happens again. Repeating an unknown trigger is not a safe diagnostic method.

How the Documented EKZ Infection Chain Unfolds

Step 1: Attackers abuse the management environment

The reported campaign involved CVE-2026-35616 in FortiClient EMS. Attackers used unauthorized management access to alter settings involved in endpoint VPN workflows.

For the reader, the important consequence is that the apparent instruction source could be a managed configuration rather than an obvious unsolicited attachment.

Administrators should assess their own deployment against the vendor’s current advisory. Do not apply a historical version list without checking the product and release actually installed.

End users should not attempt to repair a shared management server. Report the endpoint evidence to the team authorized to investigate it.

Step 2: A VPN-related workflow launches a misleadingly named payload

Arctic Wolf observed script execution associated with VPN activity and delivery of the patch-named executable. The name supplies an appearance of routine endpoint maintenance.

A file calling itself a patch is not the same as a verified vendor update. Its provenance and execution history need examination.

If your security software blocked an item, record whether the result was blocked, quarantined, or merely detected. Those outcomes can imply different exposure.

Don’t restore a quarantined file just because its name resembles approved software. Ask the responsible security team to evaluate the alert.

Step 3: Browser information is collected

The analyzed tool targets Chromium-family and Firefox-family browser information, including saved logins and cookies. Collected information is written locally for later handling.

A saved session can represent access even when you did not type a password during the incident. Include already signed-in services in the assessment.

The possible scope depends on the data available on that device. A campaign’s capabilities do not prove that every account on every computer was accessed.

Still, an absence of visible disruption is not reassuring enough. Information theft can matter while the browser continues to work normally.

Step 4: Other script activity transfers the collected output

The documented script handles exfiltration around the stealer’s local output. Investigating the executable without its surrounding process activity leaves an incomplete picture.

Security staff should preserve relevant endpoint and network records before routine cleanup destroys useful context. That decision is especially important on shared or managed infrastructure.

Device remediation cannot recall a password that has already been copied. Account protection must proceed according to the exposure identified by the investigation.

Restoring a computer to service also requires confidence that the management route will not deliver the same problem again.

Which Browser Information Deserves Immediate Attention?

Saved passwords and active sessions need separate checks

Start with services used in the affected browser. Identify which were signed in and which credentials were stored there during the suspected period.

Replace exposed passwords through the genuine services. Also inspect the session controls each service provides, rather than assuming a replacement automatically closes every connection.

Check unfamiliar devices, recovery options, and authorized applications. A compromised login may be used to establish another access method that deserves its own removal.

Email may provide a route into other accounts

A mailbox often receives password-reset links and security notifications. If it was accessible, protect it early and review changes to forwarding or filtering.

Then examine important services that use that mailbox for recovery. Look for actual reset requests and suspicious activity rather than guessing that every service was taken over.

Work accounts can require administrator assistance. The organization may need to revoke sessions or investigate records that the ordinary account holder cannot access.

Payment details call for accurate reporting

If payment information was stored or a suspicious charge appears, contact the issuer through a known number. Explain the incident without declaring an unobserved transaction fraudulent.

Keep transaction references and the period of potential exposure. The issuer can explain available controls and what additional evidence it needs.

A bank conversation should be independent of anyone who contacts you claiming to investigate EKZ. Don’t transfer funds because a stranger describes them as unsafe.

What Administrators Need Before They Call an Endpoint Clean

A workstation scan answers questions about the workstation. It does not, by itself, establish that the management server and deployment policies are trustworthy.

Separate those workstreams in the incident record. Otherwise, an endpoint may return to an environment where the original source of instructions remains unresolved.

Review unexpected management changes and identify which devices received the affected configuration. Preserve relevant logs with consistent time references.

Compare alerts across the managed group without assuming identical outcomes. One endpoint may have blocked execution while another encountered a different stage.

If business access was available, involve the owners of those systems. A technically successful cleanup does not settle whether a copied account was used elsewhere.

Document the difference between confirmed compromise and precautionary containment. That distinction makes escalation, customer communication, and recovery planning more accurate.

Use current vendor guidance for patching and support. A security advisory can change as additional fixed releases and affected configurations become clear.

A patch closes a vulnerability; it does not automatically remove previously deployed malware or invalidate secrets stolen before the patch.

Before broad credential changes, coordinate the sequence with service owners. Replacing shared access without a plan can interrupt recovery while leaving the actual compromised route active.

Likewise, do not export sensitive logs into an unapproved public tool for convenience. Browser data and deployment records may contain private information requiring controlled handling.

What to Do If EKZ Stealer Is Detected or Suspected

1. Stop sensitive work on the affected computer. Don’t log in to financial, administrative, or personal accounts while the endpoint is under assessment.

   Contact your genuine security team from another device. Follow its containment instructions, including network isolation when appropriate, without attempting an uncoordinated wipe.

2. Preserve the detection and timeline. Record the alert’s full wording, status, time, and the file involved. Note relevant VPN connections or update activity.

   Don’t execute the suspect file for confirmation. A technician can investigate safely without asking you to reproduce a potentially harmful launch.

3. Inspect Windows with trusted tools. Malwarebytes can help identify malicious and unwanted components. Use the Windows section of the reusable guide below.

   On a managed endpoint, coordinate scanning with the incident team. Its evidence-preservation and response tools may require a particular order of work.

4. Investigate management-side delivery. Authorized administrators should review the relevant EMS deployment, VPN profiles, and current vendor remediation guidance.

   Do not uninstall legitimate corporate software indiscriminately. The aim is to establish what changed, who received it, and whether the original delivery route is secure.

5. Recover exposed online access from a clean device. Prioritize valuable services and email, then change passwords and revoke suspicious sessions as the providers allow.

   Review recovery contacts and authentication methods. If an attacker altered those controls, follow the provider’s formal recovery process or your organization’s administrator-led procedure.

6. Handle financial findings through the relevant institution. Report suspicious card activity or unauthorized access with dates, references, and a clear description of what happened.

   Ask about appropriate protective steps. No security application can guarantee reimbursement, erase a remote copy of data, or reverse a transaction.

7. Choose a safe restoration plan. If the device needs rebuilding, preserve required evidence first and restore only material assessed as appropriate.

   A full old environment can restore unwanted components or settings. Agree on the source of software, the condition of backups, and who approves normal use.

8. Keep prevention tied to the actual entry route. Update systems and strengthen management access under the responsible team’s control.

   AdGuard may reduce exposure to malicious advertising during ordinary browsing. It does not repair an exploited management server or remove a compromised VPN-profile instruction.

Is Your Device Infected? Run a Free Malware Scan

Slow performance, constant pop-ups, or strange behavior? These are classic signs of a malware infection. A quick way to check is to scan your device with Malwarebytes Free, one of the most trusted malware removal tools available. If you only visited a scam page and didn’t download or install anything, this scan is optional.

The free version detects and removes the most common threats, including:

• Adware — the cause of those annoying pop-ups
• Browser hijackers — unwanted redirects and changed homepages
• Trojans and spyware — hidden programs stealing your data
• Potentially unwanted programs (PUPs) — software you never asked for

👉 Select your device below — Windows, Mac, or Android — then follow the simple steps to download Malwarebytes, scan your system, and remove any threats it finds. The scan usually takes 5 to 20 minutes.

Malwarebytes for WindowsMalwarebytes for MacMalwarebytes for Android

Run a Malware Scan with Malwarebytes for Windows

Malwarebytes is one of the most popular and trusted anti-malware tools for Windows — and it’s completely free for removing infections. It catches threats that many antivirus programs miss, including adware, browser hijackers, and trojans. Follow the steps below to scan your PC and remove what Malwarebytes finds.

1. Download Malwarebytes

   Click the button below to download the latest version of Malwarebytes for Windows from the official source. The free version is all you need — it will scan your computer and remove adware, browser hijackers, and other malicious software at no cost.

   

   Malwarebytes Free for WindowsScans and removes malware at no cost

   Download MalwarebytesOfficial installer for Windows 11 and 10. Your download starts right away.Want real-time protection? See Malwarebytes Premium

2. Install Malwarebytes

   When the download finishes, open your Downloads folder and double-click the MBSetup file. If Windows shows a User Account Control pop-up, click “Yes” to allow the installation.

   

3. Follow the On-Screen Prompts to Install Malwarebytes

   The setup wizard will walk you through a few quick screens:

   • Choose where you’re installing the program — “Personal Computer” or “Work Computer” — then click Next.

     

   • Malwarebytes will now install on your device. This usually takes under a minute.

     

   • When installation is complete, the “Welcome to Malwarebytes” screen will open automatically.

     

   • On the final screen, click Open Malwarebytes to launch the program.

     

4. Optional: Check for rootkits with a Custom Scan

   You don’t need to change any settings for a normal scan. The standard Threat Scan in the next step is enough for most problems, so you can go straight to it.

   If you also want to check for rootkits, use a Custom Scan. In current versions of Malwarebytes, rootkit scanning is only available there:

   1. On the Scanner tile, click the three-dot menu and select Advanced Scan.
   2. Choose Custom Scan. In its options, check Scan for rootkits.
   3. Select your system drive (usually C:\) as the location to scan, then start the scan. It takes longer than a Threat Scan.
   4. When it finishes, review and quarantine the results as described in the steps below.

   Rootkit scanning isn’t available on Windows devices with ARM processors.

5. Start the Scan

   Click the blue Scan button. Malwarebytes will automatically update its virus database and start checking your computer for malware.

   

6. Wait for the Scan to Finish

   The scan checks your entire system for browser hijackers and other malicious programs, so it can take 5 to 20 minutes depending on your computer. Feel free to do something else — just check back occasionally to see the progress.

   

7. Quarantine the Detected Threats

   When the scan is done, you’ll see a list of everything Malwarebytes found — malware, adware, and potentially unwanted programs. Click the “Quarantine” button to remove all of them at once.

   

   Malwarebytes will now remove the malicious files and registry entries and move them safely into quarantine.

   

8. Restart Your Computer

   Some threats can only be fully removed after a reboot. If Malwarebytes asks you to restart, click Yes. Once you’re logged back in, Malwarebytes has finished removing the threats it found.

   

When the scan is done, check whether the problems you noticed have stopped. If they continue, see the options below.

Keep your PC protectedStop the next infection before it starts

If your antivirus let this threat through, it may not be enough on its own. Malwarebytes Premium adds real-time protection that blocks malware, ransomware, and malicious websites before they can infect your computer.See Malwarebytes Premium

If you are still having problems with your computer after completing these instructions, then please follow one of the steps:

• Run a computer scan with ESET Online Scanner
• Ask for help in our Windows Malware Removal Help & Support forum.

Run a Malware Scan with Malwarebytes for Mac

Malwarebytes for Mac is a free on-demand scanner that removes the malware other security software tends to miss — adware, browser hijackers, and unwanted programs included. Cleaning an infected Mac with Malwarebytes has always been completely free, and it’s our go-to recommendation. Follow the steps below to scan your Mac and remove what Malwarebytes finds.

1. Download Malwarebytes for Mac

   Click the button below to download the latest version of Malwarebytes for Mac.

   

   Malwarebytes Free for MacScans and removes malware at no cost

   Download MalwarebytesOfficial installer for macOS. Your download starts right away.Want real-time protection? See Malwarebytes Premium

2. Open the Malwarebytes setup file

   When the download finishes, open your Downloads folder and double-click the setup file to begin the installation.

   

3. Follow the On-Screen Prompts to Install Malwarebytes

   The Malwarebytes for Mac Installer will guide you through a few quick screens. Click “Continue” and keep following the prompts until the installation completes.

   

   

   

   When the installation is complete, Malwarebytes opens to the Welcome to Malwarebytes screen. Click “Get started“.

   Malwarebytes needs Full Disk Access to check your whole Mac. When it asks, open System Settings > Privacy & Security > Full Disk Access, turn on Malwarebytes (it may be listed as Malwarebytes Protection), and confirm with your password or Touch ID. Then return to Malwarebytes. On macOS Monterey and earlier, this setting is in System Preferences > Security & Privacy > Privacy.

4. Select “Personal Computer” or “Work Computer”

   Malwarebytes will ask what type of computer you’re installing it on. Click either Personal Computer or Work Computer, whichever applies.
   

5. Start the Scan

   Click the “Scan” button. Malwarebytes will automatically update its detection database and begin checking your Mac for malware.
   

6. Wait for the Scan to Finish

   Malwarebytes will scan your Mac for adware, browser hijackers, and other malicious programs. This can take a few minutes, so feel free to do something else — just check back occasionally to see the progress.
   

7. Quarantine the Detected Threats

   When the scan is done, you’ll see a list of everything Malwarebytes found. Click the “Quarantine” button to remove all the threats at once.
   

8. Restart Your Mac

   Malwarebytes will now remove all the malicious files it found. Some threats can only be fully removed after a reboot — if Malwarebytes asks you to restart, allow it. Once you’re logged back in, check whether the problems you noticed have stopped. If they come back, save the scan report and ask for help in our forum.
   
   

If the problems you noticed continue after the scan, see the options below.

Keep your Mac protectedStop the next infection before it starts

If your Mac got infected, its built-in protection may not be enough on its own. Malwarebytes Premium for Mac adds real-time protection that blocks malware and adware before they can infect your Mac.See Malwarebytes Premium

If you are still experiencing problems while trying to remove a malicious program from your computer, please ask for help in our Mac Malware Removal Help & Support forum.

Run a Malware Scan with Malwarebytes for Android

Malwarebytes for Android scans your phone or tablet for malware, adware, and potentially unwanted apps. The free version scans only when you start a scan. Real-time protection, which checks apps automatically, is part of the paid Premium version.

1. Download Malwarebytes for Android.

   You can download Malwarebytes for Android by clicking the link below.

   

   Malwarebytes for AndroidScans your phone and removes malware at no cost

   Get Malwarebytes for AndroidOpens Google Play in a new tab.Want real-time protection? See Malwarebytes Premium for Android

2. Install Malwarebytes for Android on your phone.

   In the Google Play Store, tap “Install” to install Malwarebytes for Android on your device.

   

   When the installation process has finished, tap “Open” to begin using Malwarebytes for Android. You can also open Malwarebytes by tapping on its icon in your phone menu or home screen.
   

3. Follow the on-screen prompts to complete the setup process

   When Malwarebytes opens, it walks you through a short setup. Tap Get started and follow the prompts. If you see an offer for a trial or a paid plan, read it before you accept. You can skip it and keep using the free scanner.

   Malwarebytes will ask for permission to access the files on your phone so it can scan them. Tap Allow, or turn on the permission in the Android screen that opens, then return to Malwarebytes.

4. Run a scan with Malwarebytes for Android

   On the main screen, tap Scan now. In some versions, you open the menu, tap Scanner, and then tap Run a scan.

5. Wait for the Malwarebytes scan to complete.

   Malwarebytes will now start scanning your phone for adware and other malicious apps. This process can take a few minutes, so we suggest you do something else and periodically check on the status of the scan to see when it is finished.
   

6. Remove the detected apps.

   When the scan has been completed, you will see a list of the threats that Malwarebytes for Android has detected. Next to each detected item, tap the menu icon (three dots), then choose to uninstall the app or delete the file. Android then asks you to confirm. Tap OK or Uninstall to remove the app.

7. Restart your phone.

   When the detected apps are removed, restart your phone if Malwarebytes asks you to. Then check whether the problems you noticed have stopped.

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If the problems you noticed continue after the scan, see the options below.

Keep your phone protectedStop the next infection before it starts

Malwarebytes for Android Premium adds real-time protection that blocks malicious apps and scam links before they can harm your phone.See Malwarebytes for Android

If you are still having problems with your phone after completing these instructions, then please follow one of the steps:

• Ask for help in our Mobile Malware Removal Help & Support forum.
• Only as a last resort, reset your phone to factory settings. Read the warning below first.

A factory reset erases everything on your phone. Your apps, photos, files, and settings are deleted, so use it only if the problem continues after the steps above and after you’ve asked for help. Before you reset:

• Back up your photos, videos, files, and messages, for example to your Google account or a computer.
• Make sure you know your Google account email and password. The phone asks for them after the reset. If you changed the password recently, Google recommends waiting 24 hours before you reset.
• On a Samsung phone, also make sure you know your Samsung account password.
• If you use an authenticator app for two-step verification, move your accounts to another device or save your backup codes first.

On a Google Pixel, go to Settings > System > Reset options > Erase all data (factory reset). On a Samsung Galaxy phone, go to Settings > General management > Reset > Factory data reset. Menu names differ on other phones, so check your manufacturer’s support site.

Stay Protected: Block Ads and Malicious Sites

No scan can prove a device is completely clean, so it helps to block threats before they reach you. Most infections start with a malicious ad or a fake download button — so blocking them at the source is your best defense.

We recommend AdGuard, which blocks malicious ads, phishing pages, and dangerous redirects before they can reach you.

👉 Download AdGuard and browse safely

What a Successful Recovery Should Leave You With

You need more than a disappearing alert. Keep a record of endpoint remediation, management-side findings, and account-protection actions as separate completed tasks.

If no suspicious transaction appears, continue monitoring according to the investigation’s findings. Don’t turn an uncertain exposure into a claim of proven financial loss.

If a detection returns, preserve the new result and escalate. Repeating one cleanup step without investigating recurrence can miss the mechanism restoring the problem.

Microsoft’s malware troubleshooting guidance provides an official starting point when Windows security tools encounter removal problems.

For an organization, define who will confirm the management environment is safe before endpoints reconnect. Users should not have to infer that from a reassuring filename.

Include devices that were offline during the initial response. A computer reconnecting later should not receive an outdated configuration simply because the active fleet was already checked.

Agree how those devices will be assessed before normal VPN use resumes. This is a management decision for authorized administrators, not a workaround for individual employees.

Keep the final configuration reference with the recovery record. It gives the team something concrete to compare against if another endpoint reports related activity.

Finally, retain useful incident notes. A later account alert may need comparison with the original period, and memory becomes less reliable as normal work resumes.

Frequently Asked Questions

What is EKZ Stealer?

It is Windows information-stealing malware associated with browser data collection. The documented campaign used compromised management workflows and a misleading patch filename.

Does using FortiClient mean I am infected?

No. Product use alone is not a diagnosis. Your administrators must assess the actual configuration, exposure, deployment history, and device evidence.

Does EKZ send stolen data by itself?

The primary analysis describes local output from the stealer, with surrounding script activity transferring that data. Investigate the whole chain, not one process alone.

Will patching the management server remove EKZ?

Not automatically. Closing the vulnerability, remediating endpoints, and recovering exposed access are separate tasks that need coordinated verification.

Can changing passwords on the affected PC be unsafe?

Yes, if the computer remains compromised. Use a separate trustworthy device for account recovery while the endpoint is being assessed.

Is a clean scan proof that no data was taken?

No. A scan reports its findings at that point. Historical data exposure and remote account activity require their own investigation.

The Bottom Line

Treat EKZ Stealer removal as both an endpoint incident and an access-recovery task. Don’t trust the patch filename or stop after deleting one executable.

Involve the responsible security team, address the delivery route, and protect exposed accounts from a clean device before returning the computer to ordinary work.