QuimaRAT Malware: How the Cross-Platform RAT Steals Passwords and Controls PCs

QuimaRAT is not a harmless administration utility. It is a commercial remote access trojan built to give criminals a quiet foothold inside Windows, macOS and Linux devices.

Once active, it can steal passwords, watch the screen, record keystrokes, access the camera and microphone, move files and install additional malware. If you suspect QuimaRAT is present, disconnect the device from the internet and treat every password used on it as exposed.

QuimaRAT Malware Overview

QuimaRAT is a Java-based remote access trojan sold as a subscription service to other criminals. Its cross-platform design matters because the same malware family can be adapted for Windows workstations, Macs and Linux systems. Java also gives the operator a broad pool of potential targets instead of limiting the campaign to one operating system.

The malware is a modular toolkit rather than a single-purpose password stealer. Operators can select surveillance, credential theft, remote control, file management, network access and additional payloads. Its command protocol also leaves room for expansion, so an infection can change as the attacker enables new functions.

QuimaRAT is sold as Malware-as-a-Service, with advertised access from $150 for one month to $1,200 for a lifetime license. The developer maintains the toolkit while customers distribute it and monetize stolen access.

What QuimaRAT can do on an infected device

• Record keystrokes, take screenshots and monitor the desktop in real time.
• Steal saved browser passwords, session data and information from selected applications.
• Search for cryptocurrency wallets and replace copied wallet addresses with an attacker’s address.
• Access the webcam or microphone for covert surveillance.
• Browse, upload, download, delete and execute files remotely.
• Open a remote command shell, manage processes and install additional payloads.
• Create proxy or port-forwarding routes that help attackers reach other systems.
• Attempt to weaken security controls, establish persistence and evade routine inspection.

The exact damage depends on the modules enabled by the operator and the privileges available on the device. A home user may lose email, banking or social-media accounts. A business can face stolen documents, compromised administrator credentials, lateral movement and a second-stage ransomware attack. Because QuimaRAT is a general remote-control platform, the absence of one visible symptom does not make the infection safe.

How QuimaRAT Infects and Controls a Device

Step 1: The victim is persuaded to run a malicious file

QuimaRAT is a toolkit sold to multiple operators, so there is no single attachment name or delivery message that identifies every infection. Attackers may disguise the loader as an invoice, shared document, software update, installer, game modification or cracked application. The common point is that code controlled by the attacker must run on the target system.

Step 2: The loader checks the operating system

The Java component can determine whether it is running on Windows, macOS or Linux and then use operating-system-specific commands. This lets one malware family choose suitable folders, startup methods and supporting tools for the infected device.

Step 3: QuimaRAT establishes persistence

On Windows, persistence may involve Run keys, scheduled tasks or startup locations. Linux variants can use cron or autostart entries, while macOS infections may rely on LaunchAgents. The goal is the same: restart the trojan after a reboot and remain available to the operator.

Step 4: The malware contacts its command server

QuimaRAT opens an encrypted channel to infrastructure controlled by the attacker. The remote operator can identify the infected system, see whether it is online and issue commands without sitting in front of the device.

Step 5: Surveillance and credential theft begin

The operator can capture keystrokes, screenshots, saved credentials, browser information and application data. Remote desktop, webcam and microphone functions can reveal activity that was never stored in a file. Stolen session data may also let a criminal enter an account without immediately needing the password again.

Step 6: The attacker expands access or delivers more malware

QuimaRAT can download tools, execute commands, inject code, create network tunnels and move files. An initial espionage infection can therefore become credential theft, cryptocurrency theft, data exfiltration or a ransomware incident. That is why simply closing a suspicious window is not a meaningful response.

Warning Signs of a Possible QuimaRAT Infection

QuimaRAT is designed to be covert, and a well-configured infection may produce no obvious pop-up. Look for combinations of unusual behavior rather than waiting for one definitive warning.

• Java or an unfamiliar process repeatedly starts when the computer boots.
• Unknown scheduled tasks, startup entries, LaunchAgents, cron jobs or autostart files appear.
• The webcam or microphone activates without a program you recognize using it.
• Security tools, the firewall or system settings change unexpectedly.
• The device makes persistent outbound connections while apparently idle.
• Passwords stop working, new sessions appear, or account recovery details change.
• Copied cryptocurrency addresses change when pasted.
• Files are created, deleted or moved without a clear explanation.

A single symptom can have an innocent explanation. Several of these signs appearing together, especially after opening an untrusted file, justify isolating the device and performing a full security investigation.

What to Do If QuimaRAT May Be on Your Computer

Disconnect the device before investigating

Turn off Wi-Fi and unplug the network cable. If this is a company device, contact the security or IT team from another trusted device before shutting it down. Isolation interrupts remote commands and can limit access to other systems on the same network.

Do not change passwords on the suspected computer

A keylogger or remote screen viewer can capture the new credentials. Use a separate, clean phone or computer to change the password for your primary email first, then banking, cloud storage, work accounts, social networks and cryptocurrency services. End existing sessions and enable multi-factor authentication.

Check accounts for signs of takeover

Review login history, forwarding rules, recovery addresses, connected applications and payment activity. Remove unfamiliar devices and API access. Contact the bank or card issuer immediately if financial details were stored or entered on the infected system.

Check browser-synchronized data as well. A compromised browser profile can expose saved passwords, bookmarks, autofill details and open tabs across multiple devices. Remove the affected computer from synchronization, review recent security events and do not restore a questionable browser profile onto a freshly rebuilt system.

Preserve evidence if the device belongs to a business

Do not wipe a corporate computer before the incident-response team has collected logs and volatile evidence. The infection may be one part of a wider intrusion, and the original entry point must be found before the machine returns to the network.

Scan and remove the malware

On a personal Windows PC, run a reputable malware scan after isolation. If QuimaRAT had administrator access, security tools were disabled, or sensitive business information was present, the safest recovery is often a clean operating-system reinstall followed by restoration from a known-good backup.

If you suspect your computer is infected with malware — slow performance, pop-ups, redirects, or programs you don’t recognize — follow the free step-by-step removal guide below to find and remove it.

Remove Malware from Windows [Step-by-Step Guide]

• STEP 1: Uninstall malicious programs from Windows
• STEP 2: Reset browsers back to default settings
• STEP 3: Use Rkill to terminate suspicious programs
• STEP 4: Use Malwarebytes to remove Trojans and unwanted programs
• STEP 5: Use HitmanPro to remove rootkits and other malware
• STEP 6: Use AdwCleaner to remove malicious browser policies and adware
• STEP 7: Perform a final check with ESET Online Scanner

STEP 1: Uninstall malicious programs from Windows

First, we’ll manually check your computer for unknown or malicious programs. Adware and browser hijackers often have a working uninstall entry — removing them this way takes care of the easy part before we run the scanners.

With the malicious programs removed, you’re ready for the next step in this guide.

STEP 2: Reset browsers back to default settings

In this step, we will remove spam notifications,  malicious extensions, and change to default any settings that might have been changed by malware.
Please note that a Chrome or Edge reset turns off all your extensions, and a Firefox refresh removes them. Your bookmarks and favorites stay intact. For each browser that you have installed on your computer, please click on the browsers tab below and follow the displayed steps to reset that browser.

STEP 3: Use Rkill to terminate suspicious programs

Next, we’ll download and run Rkill to stop any suspicious processes running in the background. This prevents the malware from interfering with the removal tools in the following steps.

RKill is a program that was developed at BleepingComputer.com that attempts to terminate known malware processes so that your normal security software can then run and clean your computer of infections. When RKill runs it will kill malware processes and then removes incorrect executable associations and fixes policies that stop us from using certain tools.

1. Download Rkill.

   You can download RKill to your computer from the below link. When at the download page, click on the Download Now button labeled iExplore.exe. We are downloading a renamed version of Rkill (iExplore.exe) because some malware will not allow processes to run unless they have a certain filename.

   

   RKillStops malware processes so other tools can run

   Download RKillOpens the BleepingComputer download page in a new tab.

2. Run RKill.

   After downloading, double-click the iExplore.exe icon to kill malicious processes. In most cases, downloaded files are saved to the Downloads folder.
   The program may take some time to search for and end various malware programs.

   

   When it is finished, the black window will close automatically and a log file will open. Do not restart your computer. Proceed to the next step in this guide.

STEP 4: Use Malwarebytes to remove Trojans and unwanted programs

Now we’ll install Malwarebytes and run a full scan to detect and remove infections, adware, and potentially unwanted programs from your computer.

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.

   

STEP 5: Use HitmanPro to remove rootkits and other malware

Next, we’ll run a second-opinion scan with HitmanPro to catch Trojans, rootkits, and other malicious programs that may have survived the previous step.

HitmanPro is a second-opinion scanner — it’s designed to catch what your main antivirus might have missed. Instead of relying on a single detection engine, it checks the behavior of files in the locations where malware usually hides. Anything suspicious is checked online, where it’s analyzed by several antivirus engines in HitmanPro’s Scan Cloud.

Good news: scanning is completely free, with no limits. You only need a license when it’s time to remove what was found — and even then, you can activate a free one-time 30-day trial to remove what it finds at no cost. The trial works once per computer. After that, removal needs a paid license, and the purchase screen shows the current price.

1. Download HitmanPro

   Click the button below to download HitmanPro. Remember — the scan is free, so you have nothing to lose by checking your PC.

   

   HitmanProSecond-opinion malware scanner from Sophos

   Download HitmanProFree scan. Removing threats needs the free 30-day trial. Opens the official HitmanPro page in a new tab.

2. Install HitmanPro

   When the download finishes, open your Downloads folder and double-click the file “hitmanpro_x64.exe”. (On 32-bit Windows 10, the file is named “hitmanpro.exe”.)

   

   If a User Account Control pop-up asks whether HitmanPro can make changes to your device, click “Yes” to continue.

   

3. Follow the On-Screen Prompts

   On the HitmanPro start screen, click “Next” to begin the system scan. No lengthy setup required — it goes straight to work.

   

   

4. Wait for the Scan to Finish

   HitmanPro will now check your computer for malicious programs. This usually takes just a few minutes thanks to its cloud-based scanning.
   

5. Review the Results and Click “Next”

   When the scan is done, HitmanPro will show you everything it found. Click “Next” to remove the detected threats.

   

6. Click “Activate Free License”

   To remove the malicious files, click the “Activate free license” button. This starts your free 30-day trial — no payment details needed — and unlocks the full cleanup.
   

   When the removal is complete, HitmanPro will show a summary of everything it cleaned. Click Next, then click Reboot if prompted. If there’s no reboot prompt, click Close. Then check whether the problems you noticed have stopped. If they come back, save the HitmanPro log and ask for help in our forum.

STEP 6: Use AdwCleaner to remove malicious browser policies and adware

We’ll now use AdwCleaner to remove malicious browser policies and unwanted browser extensions — the leftovers that keep hijacking your browser settings even after the malware itself is gone.

AdwCleaner is a free on-demand scanner that specializes in adware, browser hijackers, and unwanted toolbars — the exact threats that mainstream antivirus programs often miss. It also includes tools that repair the damage malware leaves behind, like hijacked browser settings and malicious policies. It’s a quick scan that’s well worth running.

1. Download AdwCleaner

   Click the button below to download AdwCleaner — it’s free, portable, and requires no installation.

   

   Malwarebytes AdwCleanerRemoves adware and unwanted programs at no cost

   Download AdwCleanerOpens the official download page in a new tab.

2. Run AdwCleaner

   Open your Downloads folder and double-click the file named “adwcleaner.exe“. There’s no installation — the program starts right away.
   

   If Windows asks whether you want to allow AdwCleaner to run, click “Yes“. When the license agreement appears, click I agree to continue.

   

3. Leave “Reset Chrome policies” off unless you need it

   AdwCleaner can reset Chrome policies, the settings that malware sometimes uses to lock your browser so you can’t change it back. This option removes every Chrome policy, including legitimate ones set by an employer, a school, or parental-control software, so leave it off for a normal scan.

   AdwCleaner applies this option only if you run Basic Repair at the end of the cleanup. Malwarebytes advises running Basic Repair only when a support agent asks you to, and it also runs every other repair action that is turned on in the same list. If this is your own personal PC and chrome://policy in Chrome lists policies you didn’t set, ask for help in our forum instead. On a work or school computer, ask the IT administrator.

4. Start the Scan

   Click “Dashboard” on the left side of the window, then click the “Scan Now” button.

   

5. Wait for the Scan to Finish

   AdwCleaner will now check your computer for adware and other malware. This usually takes only a few minutes — it’s one of the fastest scanners around.

   

6. Quarantine the Detected Threats

   When the scan finishes, AdwCleaner lists everything it found. Review the list and uncheck any program you installed on purpose and want to keep, then click Next. If AdwCleaner also found preinstalled software, it shows that list next. Review it the same way, then click “Quarantine“. Older versions show the Quarantine button on the first list, as in the image below.

   

7. Click “Continue” to Finish the Cleanup

   Save any open work first — AdwCleaner needs to close your open programs before it can clean. When you’re ready, click the “Continue” button.
   

   AdwCleaner will now move the selected items to quarantine. If it asks you to restart your PC, allow it. When you’re back in Windows, AdwCleaner may offer a Basic Repair. Click Skip Basic Repair. Malwarebytes recommends running Basic Repair only when a support agent asks you to. Then check whether the problems you noticed have stopped.

STEP 7: Perform a final check with ESET Online Scanner

Finally, we’ll run ESET Online Scanner as a last check for anything the earlier scans missed. A clean result is a good sign, but no scanner can guarantee that a computer is malware-free.

ESET Online Scanner is a free second-opinion scanner that performs a deep, full-system check for viruses, trojans, rootkits, and other malware. We use it as the final step because it’s thorough and can catch threats the earlier scans missed. A clean result is a good sign, but no scanner can guarantee that a computer is malware-free.

1. Download ESET Online Scanner

   Click the button below to download ESET Online Scanner.

   

   ESET Online ScannerFree one-time malware scan from ESET

   Download ESET Online ScannerOpens the official download page in a new tab.

2. Run the Installer

   When the download finishes, open your Downloads folder and double-click “esetonlinescanner.exe“.
   

3. Install ESET Online Scanner

   On the start screen, select your language from the drop-down menu and click Get started.

   

   On the Terms of use screen, click Accept.
   

   Choose your preferences for the Customer Experience Improvement Program and the Detection feedback system (either choice is fine), then click Continue.
   

4. Start a Full Scan

   Click Full Scan — this checks your entire computer, not just the common hiding spots.

   

   Select Enable for Detection of Potentially Unwanted Applications — this lets ESET catch adware and bundled junk programs, not just viruses. Then click Start scan.

   

5. Wait for the Scan to Finish

   ESET will now check every file on your computer. Because it’s a full scan, this can take a while — often an hour or more, depending on how much data you have. Leave it running in the background and check on it from time to time.

   

6. Review the Results

   When the scan completes, the Found and resolved detections screen appears. Detected threats are usually cleaned and quarantined automatically. Click View detailed results to see exactly what was removed, and ask for help in our forum if any item could not be cleaned.
   

   If ESET found nothing, restart your computer and check whether the problems you noticed have stopped. If they continue, ask for help in our forum.

When you’ve finished these steps, 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.

How to Reduce the Risk of Another RAT Infection

• Install software only from the developer’s official site or a trusted app store.
• Do not open unexpected archives, scripts, installers or macro-enabled documents.
• Avoid cracks, activators and unofficial game modifications.
• Keep the operating system, browser, Java runtime and security software updated.
• Use a password manager so one stolen password does not unlock multiple accounts.
• Enable multi-factor authentication, preferably with an authenticator app or security key.
• Use a standard user account for daily activity instead of an administrator account.
• Maintain offline or versioned backups that malware cannot silently overwrite.

The Bottom Line

QuimaRAT is a serious cross-platform remote access trojan, not a routine unwanted program. Its modular design can support surveillance, password theft, file theft, cryptocurrency theft, network tunneling and delivery of additional malware.

If you think it ran on your device, isolate the system, secure accounts from a clean device and perform a full malware-removal or rebuild process. The longer a remote-access trojan remains connected, the more opportunities its operator has to turn one opened file into a much larger compromise.