BAT.Winstart: what it is and how to remove it
BAT.Winstart is a particular indication of malicious infection that appears as a detection result out of nowhere. If you get the alert often, you should clean the system properly and remove the infection as soon as possible.
Facts checked October 6, 2026. Removal steps tested on Windows 11 (26H2) and checked against Microsoft's and the browser makers' current documentation. Sections marked as our earlier report are the original text: they describe the threat as it was then and have not been reviewed since. The 2026 status, the removal steps and the questions are current.
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BAT.Winstart: summary
| Distribution | Main methods that help to distribute these infections – pirating platforms and malicious email attachments |
|---|---|
| Name | BAT.Winstart |
| Type | Trojan |
| Issues | The infection can launch additional processes, affect the speed and performance of a computer |
| Detection names | No Microsoft detection name is known |
| Damage | Not recorded in the old report |
| Removal | Scan the PC with security software to find and remove the malware and anything installed with it. Fortect scans Windows for malware and repairs the system files and settings it damaged. Remove it nowTo use the full-featured product, you have to purchase a license for Fortect. The scan is free. |
Show 5 more facts
| Symptoms | An unknown process in Task Manager |
|---|---|
| Evidence | One write-up by a security site; details still limited |
| File names | WINSTART.BAT |
| First seen | 21 April 2021 |
| Facts checked | 6 October 2026 |
What BAT.Winstart does on an infected PC
From our report of Apr 2021 · not reviewed since
WINSTART.BAT is a suspicious file that can be used as malware
BAT.Winstart is a particular indication of malicious infection that appears as a detection result out of nowhere.
If you get the alert often, you should clean the system properly and remove the infection as soon as possible. If the trojan has more time on the system, it can trigger serious damage.
This is the threat that masks dangerous activities y posing as a file known to be commonly found on the Windows machine. Trojan can be a vector for additional infections, so the machine gets more affected once the trojan is active.
This is a really dangerous trojan, which changes Windows settings by modifying WINSTART.BAT. This action is already a real threat to the stability of the infected system. What is more, this trojan is memory-resident - this allows this parasite to perform a wide variety of destructive actions in any time.
To sum everything up, this trojan is a really dangerous pest, which can cause lots of problems to the user, who has no up-to-date security installed on the PC. You should immediately search for options that could help remove the infection. We cannot stress this enough - the best option for the malware elimination - , , other AV tools.
You can get rid of the BAT.Winstart virus and eliminate other possibly related programs with such a tool and a full system scan. If you manage to clear the machine properly with the AV tool, you might still want to repair damaged parts with PC repair tools. This tool can help with affected or corrupted pieces, including system files and registry entries.
From our report of Apr 2021 · not reviewed since
Silent threats affect machines quickly
Trojan or any other virus like this is mostly spread via spam, so you should be very careful with suspicious emails and files that are typically attached to them.
Those emails should raise some questions when senders are unknown and various links or files included in the notification. Note that downloading an infected attachment may end up with this or a similar trojan horse installed on the PC.
When trying to spot a fake email, you should firstly check the sender if it is familiar and trustworthy. If you see that address has nothing to do with the company he represents.
Criminals often pose as DHL, eBay, FedEx, and other companies. You should ignore this mail or simply delete it. Also, look for typos or grammar mistakes because they can also help you notify the malicious mail.
From our report of Apr 2021 · not reviewed since
You should clear the machine fully from any trojans and other threats that damage your device
BAT.Winstart can have the functionality of the backdoor, trojan, or dropper.
Malware like this is silent and spreading around the world makes it easier to achieve malicious goals quicker. If you receive the alert about possible infection, but cannot notice any other issues with the machine - it is possible that malware is on the machine for a short time.
However, having a trojan like this can affect the machine further, so the sooner you remove BAT.Winstart, the better. Run or and make sure to follow suggestions of malware termination thoroughly. You need to double-check to ensure that all pieces get deleted. Once that is done - run a system repair check using .
From our report of Apr 2021 · not reviewed since
More from our earlier report on BAT.Winstart
- Make sure to recover after the infection by running
How to check the PC for BAT.Winstart
- File:
WINSTART.BAT
How to remove BAT.Winstart
A loader's job is to install other malware, so treat the PC as infected with more than one program until the scans are clean.
Step 1: Check where WINSTART.BAT runs from and stop it
WINSTART.BATis the part you can see, and its location tells you whether it belongs there. Right-click it on the Processes page of Task Manager and choose Open file location, then right-click the file > Properties > Digital Signatures to see who signed it.An unsigned file, or one in a user folder such as
%AppData%, is the one to remove: end the task, then delete the file.Note the folder name, because the same folder usually holds its other files. This is the same in Windows 11 and Windows 10.
Full procedure with screenshots: Close a frozen app (Task Manager, Force Quit) On uGetFix
Step 2: Delete scheduled tasks that bring it back
Open Task Scheduler from the Start menu and click Task Scheduler Library. Select each task you do not recognise and read the Actions tab:
- a task that starts a file in
%AppData%or%Temp% - runs
powershellwith a long encoded line - opens a web address belongs to BAT.Winstart or a similar program
Right-click such a task and choose Delete, and check the subfolders too. Leave tasks from Microsoft, your PC's maker and programs you use. Task Scheduler is the same in Windows 11 and Windows 10.
Windows 11: Task Scheduler Library, the task selected, the Actions tab shows the file it runs. Full procedure with screenshots: Remove what malware leaves behind in Windows
- a task that starts a file in
Step 3: Remove it from startup
Whatever BAT.Winstart installed usually starts with Windows. Open Task Manager with Ctrl + Shift + Esc, go to Startup apps in Windows 11 or the Startup tab in Windows 10, and disable what you do not know, starting with entries that have an empty Publisher column.
Open file location on the right-click menu shows the file, which helps you decide and tells you what to delete later. Disabling is safe: if something you need stops working, switch it back on.
Full procedure with screenshots: Stop apps from opening at startup On uGetFix
Step 4: Delete the folders left behind
What the uninstaller leaves behind is usually in the user folders. Open File Explorer, switch on View > Show > Hidden items (in Windows 10 View > Hidden items), and go through
%LocalAppData%,%AppData%, %ProgramData% and the two Program Files folders.Sort by Date modified and delete folders that appeared together with the problem and belong to no program you use. Folders with random names that hold
.exe,.dll, .js or .ps1 files are the strongest sign.Full procedure with screenshots: Remove what malware leaves behind in Windows
Step 5: Scan the PC, then run the offline scan
Open Windows Security > Virus & threat protection > Scan options, run a Full scan and remove everything it finds. Then select Microsoft Defender Antivirus (offline scan) and click Scan now: the PC restarts and scans before Windows loads, which finds files that hide while Windows runs.
Save your work first, because the offline scan takes about 15 minutes. Both scans are built into Windows 11 and Windows 10, and a second scanner from another vendor is a useful extra opinion.
Windows 11: Windows Security > Virus & threat protection > Scan options. Full procedure with screenshots: Run a Microsoft Defender Offline scan
Step 6: Change passwords from another device and sign out other sessions
Assume that the passwords saved in this PC's browsers, and the accounts that were open in them, are known to the attacker. From a phone or a clean computer, change the e-mail password first, then banking, shopping, social and gaming accounts.
Use each service's option to sign out of all other sessions, because stolen cookies keep a session open even after a password change. Turn on two-step verification on each account. Wait with the infected Windows 11 or Windows 10 PC until the scans are clean.
Full procedure with screenshots: Turn on two-step verification / secure a hacked account
Instructions for each browser and system
The detailed steps for every browser and system this guide covers. Open the one you use.
Repair damaged system components
Once a computer is infected with malware, its system is changed to operate differently. For example, an infection can alter the Windows registry database, damage vital bootup and other sections, delete or corrupt DLL files, etc. Once a system file is damaged by malware, antivirus software is not capable of doing anything about it, leaving it just the way it is. Consequently, users might experience performance, stability, and usability issues, to the point where a full Windows reinstall is required.
Therefore, we highly recommend using a one-of-a-kind, patented technology of repair. Not only can it fix virus damage after the infection, but it is also capable of removing malware that has already broken into the system thanks to several engines used by the program. Besides, the application is also capable of fixing various Windows-related issues that are not caused by malware infections, for example, Blue Screen errors, freezes, registry errors, damaged DLLs, etc.
- Download the application by clicking on the link above
- Click on the ReimageRepair.exe
- If User Account Control (UAC) shows up, select Yes
- Press Install and wait till the program finishes the installation process
- The analysis of your machine will begin immediately
- Once complete, check the results - they will be listed in the Summary
- You can now click on each of the issues and fix them manually
- If you see many problems that you find difficult to fix, we recommend you purchase the license and fix them automatically.
By employing , you would not have to worry about future computer issues, as most of them could be fixed quickly by performing a full system scan at any time. Most importantly, you could avoid the tedious process of Windows reinstallation in case things go very wrong due to one reason or another.
Manual removal using Safe Mode
Important! →
Manual removal guide might be too complicated for regular computer users. It requires advanced IT knowledge to be performed correctly (if vital system files are removed or damaged, it might result in full Windows compromise), and it also might take hours to complete. Therefore, we highly advise using the automatic method provided above instead.
Step 1. Access Safe Mode with Networking
Manual malware removal should be best performed in the Safe Mode environment.
Windows 7 / Vista / XP
- Click Start > Shutdown > Restart > OK.
- When your computer becomes active, start pressing F8 button (if that does not work, try F2, F12, Del, etc. - it all depends on your motherboard model) multiple times until you see the Advanced Boot Options window.
- Select Safe Mode with Networking from the list.
Windows 10 / Windows 8
- Right-click on Start button and select Settings.
- Scroll down to pick Update & Security.
- On the left side of the window, pick Recovery.
- Now scroll down to find Advanced Startup section.
- Click Restart now.
- Select Troubleshoot.
- Go to Advanced options.
- Select Startup Settings.
- Press Restart.
- Now press 5 or click 5) Enable Safe Mode with Networking.
Step 2. Shut down suspicious processes
Windows Task Manager is a useful tool that shows all the processes running in the background. If malware is running a process, you need to shut it down:
- Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
- Click on More details.
- Scroll down to Background processes section, and look for anything suspicious.
- Right-click and select Open file location.
- Go back to the process, right-click and pick End Task.
- Delete the contents of the malicious folder.
Step 3. Check program Startup
- Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
- Go to Startup tab.
- Right-click on the suspicious program and pick Disable.
Step 4. Delete virus files
Malware-related files can be found in various places within your computer. Here are instructions that could help you find them:
- Type in Disk Cleanup in Windows search and press Enter.
- Select the drive you want to clean (C: is your main drive by default and is likely to be the one that has malicious files in).
- Scroll through the Files to delete list and select the following:
Temporary Internet Files
Downloads
Recycle Bin
Temporary files - Pick Clean up system files.
- You can also look for other malicious files hidden in the following folders (type these entries in Windows Search and press Enter):
%AppData%
%LocalAppData%
%ProgramData%
%WinDir%
After you are finished, reboot the PC in normal mode.
Scan your system with anti-malware
If you are a victim of ransomware, you should employ anti-malware software for its removal. Some ransomware can self-destruct after the file encryption process is finished. Even in such cases, malware might leave various data-stealing modules or could operate in conjunction with other malicious programs on your device.
or can detect and eliminate all ransomware-related files, additional modules, along with other viruses that could be hiding on your system. The security software is really easy to use and does not require any prior IT knowledge to succeed in the malware removal process.
After removal: passwords, accounts and prevention
Your passwords after BAT.Winstart
Removing BAT.Winstart does not undo what it may already have sent out while the PC showed an unfamiliar process called WINSTART.BAT in Task Manager.
Treat saved browser passwords and logged-in sessions on this PC as known to the attacker.
From another device, change the e-mail password first and end all its sessions. Then do the same for the bank, PayPal, Microsoft, Google and Apple accounts. Stolen session cookies keep working after a password change until you sign out everywhere.
Move crypto to a new wallet created on a clean device. A step-by-step order for every kind of account is in our guide to account security after an infection.
Access your website securely from any location
When you work on the domain, site, blog, or different project that requires constant management, content creation, or coding, you may need to connect to the server and content management service more often. The best solution for creating a tighter network could be a dedicated/fixed IP address.
If you make your IP address static and set to your device, you can connect to the CMS from any location and do not create any additional issues for the server or network manager that needs to monitor connections and activities. VPN software providers like can help you with such settings and offer the option to control the online reputation and manage projects easily from any part of the world.
Recover files after data-affecting malware attacks
While much of the data can be accidentally deleted due to various reasons, malware is one of the main culprits that can cause loss of pictures, documents, videos, and other important files.
More serious malware infections lead to significant data loss when your documents, system files, and images get encrypted. In particular, ransomware is is a type of malware that focuses on such functions, so your files become useless without an ability to access them.
Even though there is little to no possibility to recover after file-locking threats, some applications have features for data recovery in the system. In some cases, can also help to recover at least some portion of your data after data-locking virus infection or general cyber infection.
Questions about BAT.Winstart
Is WINSTART.BAT safe?
It depends on where the file is and who signed it, not on the name. Open Task Manager, go to the Details tab, right-click WINSTART.BAT and choose Open file location. A file inside Program Files or System32 with a valid digital signature from a known company is usually part of a legitimate program.
A file in AppData, Temp or ProgramData with no signature, especially one that restarts itself after you end it, is suspicious. If you cannot tie the process to anything you installed, uninstall recent unfamiliar programs and run a Microsoft Defender Offline scan.
WINSTART.BAT keeps coming back. What should I do?
A process that returns after you end it has a restart mechanism, and that is a reason to treat WINSTART.BAT as unwanted. Check Settings > Apps > Startup, Task Scheduler and the Services list for entries pointing to its folder, and disable them.
Look in Installed apps for anything added the same day and uninstall it. Then delete the folder and run a Microsoft Defender Offline scan, which works before Windows starts and can remove files that are locked or hidden while the system is running.
Can I just delete WINSTART.BAT?
Deleting WINSTART.BAT by hand rarely removes BAT.Winstart. While the trojan runs, Windows may refuse to delete the file, and if you succeed, a scheduled task, a service or a second copy may bring it back at the next restart.
The file can also be only one part of the infection: loaders and remote access tools often install other programs. Use the Microsoft Defender offline scan, which removes the file together with its startup entries before Windows loads, and then check startup items and scheduled tasks as described in the plan.
Is a trojan infection worth reporting to the police?
If there was harm, yes. Unauthorised payments, accounts used for fraud, blackmail or a remote session during a scam call all belong in a report, and banks often ask for its reference number before they refund anything.
If antivirus caught BAT.Winstart before it ran and nothing was misused, there is nothing to report. Keep the evidence anyway:
- protection history
- the original download
- the dates
Businesses may also have to notify a data protection authority if personal data could have been accessed.
What are the signs of a trojan infection?
Most trojans try to leave no visible signs, so look for side effects. Common ones:
- Windows Security turned off or unable to update
- new entries in Startup apps or Task Scheduler
- programs in Installed apps you did not install
- browser settings that changed by themselves
- unusual network activity while the PC is idle
- password-reset or login-alert e-mails you did not trigger
None of these proves an infection on its own. Together with an antivirus alert naming BAT.Winstart, they are a strong reason to follow the full plan.
Should I reset my PC because of BAT.Winstart?
Only if the signs point to deeper access. Reset when you see an unfamiliar process called WINSTART.BAT in Task Manager again after removal, when Windows Security cannot start or update, when remote access tools you did not install keep appearing, or when you simply cannot trust the PC any more.
Otherwise, the plan in this guide plus an offline scan is enough. If you do reset, choose Remove everything and Cloud download for a fresh copy of Windows, restore only documents and photos, and reinstall programs from their official sites. Change important passwords from the clean system afterwards.
Can BAT.Winstart spread to other devices on my network?
Most trojans aimed at home users stay on the PC they infected, but an attacker with remote access can look at the network, open shared folders and try passwords on other devices. Loaders sometimes deliver worms or ransomware that do spread.
Disconnect the PC while cleaning, run a full scan on other Windows PCs, change the router's admin password and the Wi-Fi password if they were saved on the infected PC, and update the router's firmware. If other PCs show the same detection, treat them as infected too.
Is it safe to do online banking after seeing an unfamiliar process called WINSTART.BAT in Task Manager?
Not on that PC until it is clean. A program that produces an unfamiliar process called WINSTART.BAT in Task Manager runs with your rights and could read what you type or what the browser shows. Use a phone or another computer for banking and for changing passwords.
When the offline scan of the affected PC is clean and nothing suspicious starts with Windows any more, you can go back to using it. Check your bank statements for the past weeks either way, and call the bank if anything looks unfamiliar; banks can block cards and reset access quickly.
Why didn't my antivirus stop BAT.Winstart?
New trojan builds are packed and changed often so that signatures do not match, and some are signed with stolen or bought certificates. Many arrive inside password-protected archives, which scanners cannot open until you extract them.
Some downloads also tell the user to turn off the antivirus "because it gives false alarms", a common line in cracked software instructions. Keep real-time protection on, never disable it for an installer, and run the offline scan whenever you suspect something slipped through.
Will Fortect remove BAT.Winstart?
Fortect scans Windows for malware and unwanted programs and repairs the system files and settings they change, and its free scan shows what it finds on your PC before you decide anything.
For BAT.Winstart, follow the plan above as well: the browser steps take back permissions and settings that no scanner treats as a threat, and uninstalling the program that brought it removes the source.
Run Microsoft Defender's full scan and, if anything was found, its offline scan as a second opinion. If the symptoms are gone after the plan and both scans are clean, there is nothing more to do.
Sources
- FTC: How to recognize, remove and avoid malware (read October 6, 2026)
- Microsoft Learn: Microsoft Defender Offline (read October 6, 2026)
- Microsoft Learn: How Microsoft names malware (read October 6, 2026)