Flashback: what it is and how to remove it
Flashback virus, also known as OSX.Flashback, Fakeflash, Flashback trojan, or Trojan BackDoor.Flashback. This fraudulent Trojan horse affects Mac users and their computer systems only.
Facts checked October 7, 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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Flashback: summary
| Name | Flashback |
|---|---|
| Category | Trojan horse |
| Other names | OSX.Flashback, Fakeflash, Flashback trojan, or Trojan BackDoor.Flashback |
| Latest version | BackDoor.Flashback.39 |
| OS infected | Mac OS X |
| Technique used | The threat infiltrates the computer system by using a fake Adobe Flash Player installer named "Flashback" |
| 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 8 more facts
| Symptoms | Malicious components injected, high CPU/GPU usage, software crashes, system struggles, etc. |
|---|---|
| Distribution sources | Malware-laden websites, rogue email attachments, etc. |
| Detection names | No Microsoft detection name is known |
| Damage | Not recorded in the old report |
| Type | Loader |
| Evidence | 6 write-ups by security sites; details still limited |
| First seen | 19 December 2018 |
| Facts checked | 7 October 2026 |
What Flashback does on an infected PC
From our report of Dec 2018 · not reviewed since
Flashback virus - a malicious Trojan horse which targets Mac OS X users
Flashback virus, also known as OSX.Flashback, Fakeflash, Flashback trojan, or Trojan BackDoor.Flashback.
This fraudulent Trojan horse affects Mac users and their computer systems only. The dangerous infection uses a tricky Adobe Flash Player installer with the name "Flashback" in order to infiltrate the victims' computer systems. It is very important to know that infections such as trojan ones are capable of secretly hiding on the infected machine and performing hazardous activity silently.
Flashback trojan can also be very dangerous if kept on the system for a long time. A trojan infection can relate in many things such as the injection of other viruses, identity theft, program crashes or corruption, system sluggishness or unrepairable damage, high CPU and GPU usage, etc.
Talking about April 2012, when the Trojan horse was first launched, it made attempts against numerous Mac users worldwide. According to research, most people that were infected lived in The United States - about 56%, after that in Canada - 19.8%, United Kingdom - 12.8%, and in Australia - 6.1%. Furthermore, the trojan was modified into a more modern one called BackDoor.Flashback.39 and discovered in April 2017.
A report claimed that this dangerous virus infected numerous Mac machines by creating a botnet which contains 274 bots. This variant targeted Java vulnerabilities which were found on the Mac PC. Moreover, the trojan injected a malicious executable to be able to run a specific code from a remote server. Additionally, this version of the Flashback virus was able to infect only those users who visited the malware-laden website.
As we can see, Flashback virus is an extremely malicious trojan which has been active for several years. Such infections can cause unrepairable damage to your computer system or even relate in sensitive data losses. Even though Trojan horses do not show any particular symptoms, sometimes they can be identified from these signs:
If you spot the beforementioned symptoms, make sure you remove Flashback virus from the system as soon as possible. For this purpose, you should use only reliable and expert-tested computer security tools that will complete the process effectively. Furthermore, make sure that all malware-laden components are also found. For this, we suggest downloading and installing a computer program such as .
Performing the Flashback trojan removal requires a big variety of skills. This is the main reason why the Trojan horse cannot be eliminated by using manual technique.
If you decide to get rid of the dangerous computer infection on your own, you might cause even more trouble or damage the system. However, it is advisable to boot the computer to Safe Mode with Networking that might help you to disable some malicious activities.
Flashback virus seems to be extremely malicious as it is very hard to terminate. According to cybersecurity researchers, once the malicious attacks had emerged in the past years, Apple decided to release Java Runtime Environment (JRE) which would be a way to deal with the dangerous malware and would be available not only on Mac but also on other operating systems such as Windows, Linux, and Solaris.
However, the release did not come out and did not stop the trojan from infecting numerous Mac users in 2014.
- the CPU and GPU usage has increased highly recently;
- various programs start crashing or fail while loading;
- you have found unrecognizable components or files inside the system;
- computer sluggishness has appeared.
From our report of Dec 2018 · not reviewed since
Trojan avoiding methods
According to the specialists' team from NoVirus.uk, Trojan horses can be distributed in a few ways.
The most common distribution sources are malware-laden websites, phishing email campaigns, and rogue attachments. Even though these cyber threats are extremely sneaky, you can take some precautionary measures to avoid them from infiltrating your Mac or Windows computer:
Furthermore, a good option would be to purchase a reliable anti-malware program. Our suggestion would be not to be afraid to invest in a truly reputable and effective tool. Remember that the antivirus needs to be updated once in a while. If taken care of properly, the computer security software will allow you to perform regular system scans and alert if some malicious components are found.
- install all recommended updates, do not keep any not-updated software on your computer;
- do not open any rogue files or documents that come clipped to spam messages;
- avoid entering unrecognizable links or visiting questionable pages;
- do not download any programs or components that do not come from original websites;
- install updates from your operating system ONLY from authorized web pages.
From our report of Dec 2018 · not reviewed since
More from our earlier report on Flashback
- Use reputable tools for the removal only.
- Moreover, install to find all dangerous files and other components in the Mac computer system
How to remove Flashback
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
Programs like Flashback add a scheduled task so they return after an uninstall or reopen a page at every sign-in. Start Task Scheduler, open Task Scheduler Library and sort by Last Run Time to see what ran recently.
On the Actions tab, a program in a user folder, a script or a web address is a warning sign; right-click such a task and choose Delete.
Tasks with names copying Google, Edge or Windows updaters but pointing to an odd folder are typical. The tool looks 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
Step 2: Remove it from startup
Press Ctrl + Shift + Esc to open Task Manager and select Startup apps (Windows 11) or the Startup tab (Windows 10). Disable entries you do not recognise, especially ones with no publisher or with a name that copies a Windows component.
Right-click an entry and choose Open file location to see where it runs from: programs in
%AppData%or%Temp%deserve a closer look. Some entries are not listed there but in the registry Run keys, which the procedure below shows how to check.Full procedure with screenshots: Stop apps from opening at startup On uGetFix
Step 3: Delete the folders left behind
Uninstalling often leaves the program's folders, and some threats reinstall themselves from them.
Press Windows + R, type
%LocalAppData%and press Enter, then do the same for%AppData%and %ProgramData%, and look for folders named after Flashback, its publisher or created on the day the problem started. Delete those folders, and check C:\Program Files and C:\Program Files (x86) too.If Windows says a file is in use, end it in Task Manager or delete the folder after a restart in Safe Mode. The folders are the same in Windows 11 and Windows 10.
Full procedure with screenshots: Remove what malware leaves behind in Windows
Step 4: Scan the PC, then run the offline scan
A scan finds the parts of Flashback that the manual steps cannot see. In Windows Security > Virus & threat protection > Scan options, start a Full scan and quarantine what it reports.
Follow it with Microsoft Defender Antivirus (offline scan) > Scan now, which restarts the PC and checks the disk while Windows and the malware are not running.
It takes about 15 minutes and works the same in Windows 11 and Windows 10. If either scan finds something, run the full scan again after removal until it comes back clean.
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
Flashback can copy saved passwords, cookies and session tokens and send them out in seconds, so cleaning the PC does not undo the theft.
Change your passwords on a device that was never infected, starting with the e-mail account, since every other reset goes through it. On each account, end all other sessions and check the recovery e-mail, phone number and forwarding rules.
Then turn on two-step verification. Sign in on the Windows 11 or Windows 10 PC again only after the offline scan is 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 Dec 2018 · not reviewed since
Remove OSX.Flashback
Once spotted in the Mac operating system, the trojan infection needs to be removed ASAP.
To remove Flashback virus, you will need to lean on reputable antivirus tools that will complete the process effectively.
After you perform the Flashback trojan removal, make sure that you perform some system backups. This action will ensure you that the cyber threat was eliminated successfully and is no longer active in the system. Furthermore, do not forget to memorize all trojan avoiding techniques. Perform such steps in the feature to avoid similar infections and keep your Mac or Windows computer safe from damage.
[GI=method-1]Turn on the Safe Mode with Networking function to deactivate the dangerous computer virus:
[GI=method-2]Activate System Restore on your computer system by following these below-given steps:
After removal: passwords, accounts and prevention
Your passwords after Flashback
Removing Flashback does not undo what it may already have sent out while the PC showed flashback in the list of installed apps.
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 Flashback
Can I safely uninstall Flashback?
If you did not install Flashback yourself and it is not part of your hardware or a program you rely on, yes. Uninstalling an unwanted program does not harm Windows. Before you do, search the exact name and publisher to be sure it is not a driver tool, a printer utility or a game launcher with an odd name.
Then remove it from Settings, Apps, Installed apps. Ignore any offers or warnings in its uninstaller about losing protection or performance. Afterwards check Startup apps and your browsers for leftovers, and restart once to confirm that it does not reinstall itself.
How do I stop programs like Flashback from being installed again?
Most unwanted programs arrive through installers, so the fix is in how you install software. Download programs from their official sites or the Microsoft Store, not from download portals or ads above search results. During setup, choose Custom or Advanced installation and untick every extra offer, including browsers, toolbars and optimizers.
Decline update prompts that appear inside other programs unless you know them. In Windows Security, turn on reputation-based protection and potentially unwanted app blocking. These steps would most likely have stopped Flashback before it reached the app list.
Do I need to reinstall Windows to get rid of Flashback?
Usually not. A thorough clean-up is enough when the offline scan finds nothing afterwards and you do not see flashback in the list of installed apps again. A reset is the safer choice if an attacker had remote control, if security tools were switched off, or if detections come back after every clean-up.
Windows 11 can reset itself without a USB stick under Settings > System > Recovery > Reset this PC. Copy documents and photos out first and scan the copies. A reset does not change passwords or undo stolen data, so the account steps still apply.
I found AnyDesk or ScreenConnect that I did not install. Is that Flashback?
Not necessarily Flashback, but it is a warning sign. These are legitimate remote support tools, and criminals use them as ready-made backdoors, especially after tech support scams or fake invoice calls.
If you did not install it and no one you trust set it up, uninstall it, change passwords from a clean device and check your bank account. If someone connected to your PC through it, follow the steps for remote access trojans and consider a Windows reset. Installed apps sorted by date shows when it appeared.
My antivirus was on. How did a trojan get past it?
Antivirus programs see a file only when it is written or run, and criminals test each new build against popular scanners before release. Detection catches up within hours or days, which is often after the first victims ran it.
Archives with passwords, installers that fetch the malware later, and scripts run through PowerShell make the job harder. That is why behaviour such as downloading cracks or pasting commands matters more than any setting. Keep Windows and Defender updated, and turn on Reputation-based protection in App & browser control.
How do I know if my PC has Flashback?
Often you do not, which is the point of a trojan. Possible signs are an antivirus alert naming Flashback or a generic trojan detection, unknown programs or scheduled tasks, processes with random names in Task Manager, browser extensions you did not add, security settings turned off, slower performance, or account alerts about logins from unknown places.
The reliable check is a full scan followed by Microsoft Defender's offline scan. If you recently ran a crack, a fake installer or a command a website told you to paste, scan even without symptoms.
Should I check my other computers too?
Yes, it takes little time and removes doubt. Flashback itself usually stays on one PC, but the download that carried it may have been copied to other computers, shared drives may hold the same installer, and an attacker who had access could have tried saved passwords on other devices.
Run a full scan on every Windows PC in the home or office, check shared folders for the original download, and change Wi-Fi and router passwords if they were stored on the infected machine.
Which malware family is Flashback?
That is not known yet. Flashback has been reported by people who saw flashback in the list of installed apps, but no sample has been analysed publicly, so security companies have not assigned it to a family. The name you see may be a file or program name chosen by the authors, not a family name.
This does not stop you from removing it: the startup points, the offline scan and the account steps are the same for most families of this type. If Microsoft Defender or another scanner gives the file a detection name, write it down; that name is the best clue to the family and is useful when you report the incident.
Should I report Flashback?
Report it if you lost money, if accounts were taken over, if you are a business, or if the trojan came through a scam call. A police or national cybercrime report gives you a reference number for your bank and insurer and helps link cases.
You do not need to report a trojan that antivirus blocked before it ran. Before reporting, write down the dates, the detection name, file names and any messages or transactions linked to the attack; screenshots of antivirus alerts are useful evidence. The country list is in the report section above.
Will Fortect remove Flashback?
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 Flashback, 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
- Search Security: Trojan horse (computing) (read October 7, 2026)
- CNET: Mac Flashback malware: What it is and how to get rid of it (FAQ) (read October 7, 2026)
- Wikipedia: Flashback (Trojan) (read October 7, 2026)
- Mashable: What's the Worst the Mac Flashback Trojan Could Do? (read October 7, 2026)
- Mac world: What you need to know about the Flashback trojan (read October 7, 2026)