JackServn: what it is and how to remove it
JackServn Trojan is a dangerous computer threat which might be programmed to perform multiple malicious actions to harm victim's computer system or even hardware. Unfortunately, experts are still determining its primary function, and no reliable information could confirm its capabilities.
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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JackServn: summary
| Damage | Might be using an excessive amount of CPU power to mine cryptocurrency, open backdoors to infect the PC with other malicious programs or steal sensitive data |
|---|---|
| Name | JackServn |
| Type | Trojan |
| Danger level | High |
| Detection names | No Microsoft detection name is known |
| Distribution | 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 4 more facts
| Symptoms | An unknown program in Installed apps |
|---|---|
| Evidence | 4 write-ups by security sites; details still limited |
| First seen | 14 May 2018 |
| Facts checked | 6 October 2026 |
What JackServn does on an infected PC
From our report of May 2018 · not reviewed since
More from our earlier report on JackServn
- You can uninstall JackServn Trojan with a robust security software only.
What JackServn can steal or download
From our report of May 2018 · not reviewed since
JackServn Trojan is a dangerous computer threat which might be programmed to perform multiple malicious actions to harm victim's computer system or even hardware.
Unfortunately, experts are still determining its primary function, and no reliable information could confirm its capabilities. Likewise, people should be extremely cautious of this cyber threat.
It is essential to keep in mind that Trojan horses can sneak into your computer secretly. Thus, many people do not notice it until this cyber threat starts damaging the system or even hardware. Likewise, we suggest you check your computer regularly and remove JackServn if detected.
Usually, malware of this type is designed for multiple purposes. One of them is to exploit victim's computer power to mine digital currency. Unfortunately, high CPU usage leaves no power for fundamental system processes and PC starts to freeze, programs may crash, and it might become unusable in the long-run.
Furthermore, once JackServn Trojan settles on your system, it can let not only other malicious program inside but also gather personal and important information. For example, banking details, credentials, logins and passwords, etc. Note that the collected data is sent directly to the cybercriminals and you can experience financial losses or face other problems.
Likewise, we strongly suggest you take care of your computer and complete JackServn removal as soon as possible if it is present on your system. For that, use the instructions at the end of this article which will explain how to prepare your PC for the elimination and get rid of this cyber threat.
How JackServn got on your PC
From our report of May 2018 · not reviewed since
As we have already mentioned, people might not even notice that JackServn Trojan is on the system since it is distributed via deceptive techniques.
Firstly, hackers place the malware on peer-to-peer (P2P) file-sharing sites where computer users usually come to download software cracks or other illegal files.
Keep in mind that the Trojan horse might disguise as such crack or other innocent software while in reality, it is designed to infect your computer and perform malicious activity. For this reason, we strongly suggest you download programs only from legitimate and official websites, using a direct link if possible.
Another popular malware distribution method is to send malicious spam emails which are holding the infected attachment. Criminals impersonate invoices from well-known companies to trick people into opening the letter together with the added file this way letting the Trojan inside.
Thus, you should pay extreme attention to the emails you receive — open only those from reliable senders and delete others without even opening them. Also, you can keep your computer protected at all times if you employ a professional malware removal software.
How to remove JackServn
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: 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 JackServn 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 2: Remove it from startup
Whatever JackServn 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 3: 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 4: 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 5: 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.
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.
From our report of May 2018 · not reviewed since
Get rid of JackServn Trojan and ensure your computer's well-being
JackServn virus is a tricky cyber infection which might not only hide its presence but also let other malware inside your system.
Likewise, you should not delay its elimination if you want to make sure that your computer, sensitive data and additional information is safe.
Unfortunately, manual JackServn removal is not an option. According to Losvirus.es team, this dangerous malware has numerous elements that are placed all across your system and might even be named as legitimate processes. Likewise, trying to identify and eliminate them all by yourself is impossible.
Thus, you should remove JackServn Trojan only automatically. These security programs are tested and highly favored by our IT experts. Keep in mind that by installing them you ensure that your computer is protected at all times.
If you want to uninstall JackServn Trojan easier, check the instructions down below. They will show you how to prepare your system for the elimination and make sure that this cyber threat won't reappear once deleted.
[GI=method-1]In some cases, sophisticated infections can try to block the antivirus. Thus, you should boot your PC into Safe Mode with Networking.
[GI=method-2]If the first method didn't help, try rebooting your computer to Safe Mode with Command Prompt.
After removal: passwords, accounts and prevention
Secure your accounts after the clean-up
Assume that whatever was saved in the browsers on this PC while the PC showed jackServn in the list of installed apps has been copied:
- passwords
- cookies
- autofill data
Work from a clean device, or from this PC once the offline scan finds nothing.
Start with your main e-mail account, because it can reset everything else, then banking and payment, then social and gaming accounts. Change each password, sign out of all sessions and turn on two-step verification: Turn on two-step verification / secure a hacked account.
The full order, including crypto wallets and card replacement, is in securing your accounts after malware.
Protect your privacy - employ a VPN
There are several ways how to make your online time more private - you can access an incognito tab.
However, there is no secret that even in this mode, you are tracked for advertising purposes. There is a way to add an extra layer of protection and create a completely anonymous web browsing practice with the help of VPN. This software reroutes traffic through different servers, thus leaving your IP address and geolocation in disguise.
Besides, it is based on a strict no-log policy, meaning that no data will be recorded, leaked, and available for both first and third parties. The combination of a secure web browser and VPN will let you browse the Internet without a feeling of being spied or targeted by criminals.
No backups? No problem. Use a data recovery tool
If you wonder how data loss can occur, you should not look any further for answers - human errors, malware attacks, hardware failures, power cuts, natural disasters, or even simple negligence.
In some cases, lost files are extremely important, and many straight out panic when such an unfortunate course of events happen. Due to this, you should always ensure that you prepare proper data backups on a regular basis.
If you were caught by surprise and did not have any backups to restore your files from, not everything is lost. is one of the leading file recovery solutions you can find on the market - it is likely to restore even lost emails or data located on an external device.
Questions about JackServn
Is JackServn a virus?
Most programs that appear the way JackServn did are not viruses in the strict sense. They are potentially unwanted programs:
- real software that arrives bundled with other downloads and then shows offers
- changes browser settings
- starts with Windows
Some are harmless, some are annoying and a few carry adware. What makes it worth removing is that you did not choose it.
Uninstall it from Installed apps and check the startup list and the browsers for anything added the same day. If it refuses to uninstall or returns after a restart, treat it as more serious and run a Microsoft Defender offline scan.
JackServn will not uninstall. What can I do?
First restart the PC and try again, because the program may have been running and locked its own files. If the uninstaller is missing or fails, start Windows in Safe Mode, where most third-party programs do not start, and remove JackServn from Installed apps there.
If it still refuses, delete its startup entry and its scheduled task, restart, and try once more. A program that actively prevents removal is behaving like malware, so finish with a Microsoft Defender offline scan. Avoid third-party uninstallers offered on search ads; several of them are unwanted programs themselves.
Can a normal remote support program be a backdoor?
Yes. Tools such as AnyDesk, TeamViewer and ScreenConnect are legitimate, but whoever controls the account behind them controls the PC. Scammers install them during fake support calls, and some trojan campaigns install them silently because antivirus programs do not flag a genuine, signed product.
If you find one you did not set up, uninstall it, check Startup apps for related entries and change passwords from another device. If money or accounts were involved, call your bank and report the incident.
Should I reset my PC because of JackServn?
Only if the signs point to deeper access. Reset when you see jackServn in the list of installed apps 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.
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 JackServn 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 JackServn, they are a strong reason to follow the full plan.
How dangerous is JackServn?
Treat it as serious until proven otherwise. The visible sign is jackServn in the list of installed apps, and programs that behave this way often have more abilities than they show:
- copying passwords
- downloading other malware
- giving remote access
Its family is not known yet, so nobody can say which of these it uses. The good news is that the response is the same in every case and takes about an hour:
- cut the network
- remove the startup entry
- run an offline scan
- change passwords from a clean device
If someone had remote control, a full reset is safer.
Can JackServn 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.
Why didn't my antivirus stop JackServn?
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 JackServn?
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 JackServn, 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
- TechTarget: Trojan horse (computing) (read October 6, 2026)
- LosVirus: LosVirus (read October 6, 2026)
- 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)