sychost.exe: what it is and how to remove it
Sychost.exe is a trojan that can damage the machine by running malicious processes in the background without users' knowledge. The particular name of the file is resembling the safe system piece svchost.exe, so people are less likely to notice the suspicious process, and the malware can run for a longer period.
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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Sychost.exe: summary
| Distribution | it comes from malicious spam emails or during the pirating processes |
|---|---|
| Name | sychost.exe |
| Type | Trojan |
| Issues | The system gets affected when malicious processes running in the background using resources of the PC |
| 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 | sychost.exe |
| First seen | 14 April 2021 |
| Facts checked | 6 October 2026 |
What sychost.exe does on an infected PC
From our report of Apr 2021 · not reviewed since
sychost.exe is a malicious process related to LEOX.B virus
Sychost.exe is a trojan that can damage the machine by running malicious processes in the background without users' knowledge.
The particular name of the file is resembling the safe system piece svchost.exe, so people are less likely to notice the suspicious process, and the malware can run for a longer period.
It is a dangerous threat to your system and therefore, should be removed immediately after detection if your AV tool indicated any issues with the file. However, that is not happening when you don't have a trustworthy tool on the PC.
sychost.exe is considered a trojan because various detections show the suspicious file origin and indicate the process as possibly dangerous. You, unfortunately, cannot find the particular program or the file itself to remove it. This is where anti-malware tools come for help.
You should rely on the anti-malware tool like or and run the proper system scan, so the infection is treated as it is supposed to. When you delete the sychost.exe virus this way, you can be sure that other malware pieces are not left behind. Double-checking is important because malware can install other files and programs on the machine.
The .exe extension of a file name means that the piece is an executable file. In some cases, executable files can damage your computer if related to malware or affected by it. You need to check for damaged pieces with proper tools like PC repair or optimization app.
From our report of Apr 2021 · not reviewed since
Malware finds the way to a computer without users notice
People still tend to rely on downloading cracked applications.
This is illegal to get a free copy of a piece of software. In addition, such cracked software or activation key generator may conceal malware like the trojan. Downloading any free programs can be dangerous and lead to infections.
Opening infected attachments from emails that are sent from suspicious companies can immediately result in cyber infection. You notice a strange email with an important attachment, like an invoice or a delivery receipt, but you haven't ordered anything? It is possible that the file attached, when opened, is triggering the trojan code drop.
Visiting shady websites is always risky, so you need to avoid such behavior. Malware can infect your computer in a matter of seconds when you click on the dangerous malware code without knowledge.
From our report of Apr 2021 · not reviewed since
Check if the malicious file gets detected by AV tools
Malware like the sychost.exe virus can run in the background and trigger all the malicious actions like making cryptocurrency, use the resources of the machine, install other threats and trigger different issues. However, in most cases, these threats are not noticeable to the user until the detection pop-up appears.
You can remove sychost.exe with tools like or because these applications can scan the machine and find threats like this. The removal procedure starts, and all malicious pieces get deleted. Also, you should double-check to make sure that all related threats are eliminated.
Once you are happy with the termination of the infection, you can move on with the system repair. You must check for damaged data in system folders and other parts with or a similar application. This piece of software can show affected parts and fix them by replacing the altered files with safe and complete data.
From our report of Apr 2021 · not reviewed since
More from our earlier report on sychost.exe
- You should remove the threat with anti-malware tools
- There are many parts that this virus can damage, so run to fix those parts
How to check the PC for sychost.exe
- File:
sychost.exe
How to remove sychost.exe
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 sychost.exe runs from and stop it
sychost.exeis 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 sychost.exe 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 sychost.exe 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 sychost.exe
Removing sychost.exe does not undo what it may already have sent out while the PC showed an unfamiliar process called sychost.exe 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.
Do not let government spy on you
The government has many issues in regards to tracking users' data and spying on citizens, so you should take this into consideration and learn more about shady information gathering practices.
Avoid any unwanted government tracking or spying by going totally anonymous on the internet.
You can choose a different location when you go online and access any material you want without particular content restrictions. You can easily enjoy internet connection without any risks of being hacked by using VPN.
Control the information that can be accessed by government any other unwanted party and surf online without being spied on. Even if you are not involved in illegal activities or trust your selection of services, platforms, be suspicious for your own security and take precautionary measures by using the VPN service.
Backup files for the later use, in case of the malware attack
Computer users can suffer from data losses due to cyber infections or their own faulty doings.
Ransomware can encrypt and hold files hostage, while unforeseen power cuts might cause a loss of important documents. If you have proper up-to-date backups, you can easily recover after such an incident and get back to work. It is also equally important to update backups on a regular basis so that the newest information remains intact - you can set this process to be performed automatically.
When you have the previous version of every important document or project you can avoid frustration and breakdowns. It comes in handy when malware strikes out of nowhere. Use for the data restoration process.
Questions about sychost.exe
Is sychost.exe a virus?
The name sychost.exe is not enough to say. Malware often uses technical-sounding names, and harmless updaters often use odd ones. Check three things:
- the folder the file runs from
- the Digital Signatures tab in its properties
- the program that starts it (Startup apps, Task Scheduler or services)
A signed file from a company whose product you use is almost certainly fine. An unsigned file in a user folder that no installed program explains should be removed, and the PC scanned with Microsoft Defender in offline mode.
sychost.exe 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 sychost.exe 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 sychost.exe?
Deleting sychost.exe by hand rarely removes sychost.exe. 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 sychost.exe 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.
Should I reset my PC because of sychost.exe?
Only if the signs point to deeper access. Reset when you see an unfamiliar process called sychost.exe 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.
Why didn't my antivirus stop sychost.exe?
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.
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 sychost.exe, they are a strong reason to follow the full plan.
Can sychost.exe 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.
Can I keep using the PC while sychost.exe is on it?
Not for anything that matters. As long as the program behind an unfamiliar process called sychost.exe in Task Manager runs, it can see what you type and what the browser stores, and it may download more malware. Disconnect the PC from the internet while you remove it, and do your banking, e-mail and password changes from another device.
Once the offline scan finds nothing and the sign does not return after a few restarts, normal use is fine. If the scan keeps finding new items, or you cannot remove the startup entry, a reset of Windows is the safer choice.
Will Fortect remove sychost.exe?
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 sychost.exe, 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)