Zonebac: what it is and how to remove it
Zonebac trojan is a backdoor type of virus that allows attackers to perform several malicious acts on victims' devices. The primary executable runs as Isasss.exe in the Task Manager after the malicious payload is executed via UPX packer.
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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Zonebac: summary
| Detection names | No Microsoft detection name is known |
|---|---|
| Distribution | Not recorded in the old report |
| Damage | Not recorded in the old report |
| Name | Zonebac |
| Type | Loader |
| Symptoms | An unknown process in Task Manager |
| 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
| Evidence | One write-up by a security site; details still limited |
|---|---|
| File names | Isasss.exe |
| First seen | 7 August 2018 |
| Facts checked | 6 October 2026 |
What Zonebac does on an infected PC
From our report of Aug 2018 · not reviewed since
Be cautions while opening spam emails and browsing the internet
You should be aware that not taking cybersecurity seriously might lead to severe consequences, like identity fraud.
Unfortunately, not many users take actions to prevent such a horrific scenario until it is too late. Therefore, security experts recommend using these precautions online:
- Download and install security software. The is one of the most crucial steps in preventing malware. Make sure you install reputable software that is capable of preventing most viruses from entering your machine.
- Update your operating system and software on time. Software developers constantly release security patches. These updates fix software vulnerabilities that can be used by cybercriminals to inject malware.
- Beware of spam emails. Malware authors often employ bots to send out thousands of phishing emails. These fake messages either include a malicious attachment or a disguised hyperlink that leads to virus infiltration. Therefore, learn to recognize phishing emails to avoid such attacks.
- Stay aware from pirated software and file-sharing sites. Torrent and similar websites are largely infested with malware. Thus, downloading and executing files from such unsafe sites is extremely dangerous.
- Use strong passwords. Using the same password for multiple websites is not a wise idea, especially if it is easy to guess.
From our report of Aug 2018 · not reviewed since
More from our earlier report on Zonebac
- Install unwanted software/malware, steal sensitive data
- Can cause information leak and inject malware
What Zonebac can steal or download
From our report of Aug 2018 · not reviewed since
Zonebac trojan is a backdoor type of virus that allows attackers to perform several malicious acts on victims' devices.
The primary executable runs as Isasss.exe in the Task Manager after the malicious payload is executed via UPX packer. There are several different variants of Win32/Zonebac malware, and most of them are known to terminate firewall and security software. Additionally, it allows the attackers to upload unwanted applications or install other viruses on the hijacked computer.
Zonebac virus is likely to infiltrate computers that are unprotected by security software. Therefore, it is vital to obtain reliable security software (experts recommend or ) and keep it updated at all times. In case your device got infected, you can remove Zonebac trojan using anti-malware tools without much effort.
To begin its malicious operation, Zonebac malware creates a 123.pid file in the Temporary files folder. From that point, it scans the computer for several executable files that are connected with security software or firewall. If found, Zonebac will terminate these processes. Additionally, malware is capable of self-destruction before security software can intervene.
Zonebac adds the value Lexmark_X74-X755 with data lsasss.exe to the HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run subkey, ensuring that the virus will run with every boot of Windows.
All the computer modifications allow hackers to perform the following:
Unfortunately, victims will have a hard time recognizing the Backdoor.Win32.Zonebac infection, as trojans generally emit no visible symptoms. Nevertheless, users can encounter system/software freezes or crashes, the slowdown of the device, an increased amount of ads on Google Chrome Internet Explorer or Mozilla Firefox, as well as security software malfunctioning. Additionally, advanced users can check for altered registry values and presence of System32\lsasss.exe.
If you suspect that your system has been infected with a trojan, make sure you scan it with anti-malware tool and remove Zonebac virus safely. If not, your personal information might be stolen and result in identity theft or money loss.
- Start or terminate various processes on the computer;
- Install additional software or malware on the device;
- Upload technical information to various remote servers;
- Upload sensitive information to remote servers;
- Take screenshots or use the camera remotely, etc.
How to check the PC for Zonebac
- File:
Isasss.exe
How to remove Zonebac
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 Isasss.exe runs from and stop it
Isasss.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 Zonebac 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 Zonebac 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.
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 Aug 2018 · not reviewed since
Eliminate Zonebac using reliable security software
To remove Zonebac virus from your PC, you need to scan it with reputable anti-malware software.
However, any other powerful tool will do the job too. However, make sure that the software's database is the latest version before scanning your computer.
We do not recommend performing Zonebac removal manually, because the trojan made several changes to the system. To revert them, an exceptional IT knowledge is required. Therefore, if you are an average computer user, pick automatic virus removal instead.
To make sure that the Zonebac trojan does not prevent malware-removal software from starting, enter Safe Mode with Networking as explained below.
[GI=method-1]To avoid Zonebac virus from disabling security software, enter Safe Mode with Networking:
[GI=method-2]You can also disable the malware by using System Restore:
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 an unfamiliar process called Isasss.exe in Task Manager 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.
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 Zonebac
Is Isasss.exe 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 Isasss.exe 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.
Can I delete the Isasss.exe file?
Only after you know what it belongs to. If Isasss.exe is part of a program, uninstall that program through Settings instead, so its services and tasks go too. If it belongs to nothing and is unsigned, end the process, disable whatever starts it and then delete its folder.
Do not delete files from the Windows folder or files signed by Microsoft: those are part of the system, and removing them can stop Windows from starting. When in doubt, run a Microsoft Defender scan first and let it decide.
Can I just delete Isasss.exe?
Deleting Isasss.exe by hand rarely removes Zonebac. 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.
Should I reset my PC because of Zonebac?
Only if the signs point to deeper access. Reset when you see an unfamiliar process called Isasss.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.
Is it safe to do online banking after seeing an unfamiliar process called Isasss.exe in Task Manager?
Not on that PC until it is clean. A program that produces an unfamiliar process called Isasss.exe 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.
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.
Can Zonebac 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 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 Zonebac 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.
Why didn't my antivirus stop Zonebac?
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 Zonebac?
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 Zonebac, 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)