Short bio

Trojan.FBSpammer is Malwarebytes’ detection name for a family of Firefox extensions that are designed to spam Facebook groups.


Users of affected systems may notice a Firefox extension that is called Page Update and the corresponding .xpi file has a random name consisting of capital characters and underscores.

Page Update extension

Users may also notice posts made on their behalf on Facebook groups they did not join themselves.

Type and source of infection

Trojan.FBSpammer is a Firefox extension that joins multiple Facebook groups and starts posting in them on behalf on the victim.
Trojan.FBSpammer is installed from websites that offer it as a Flash update.

fake Flash update


Both the Web protection module and the Malwarebytes browser extension block the websites pushing this malicious extension.

Malwarebytes browser extension


Malwarebytes can detect and remove Trojan.FBspammer without further user interaction.

  1. Please download Malwarebytes to your desktop.
  2. Double-click MBSetup.exe and follow the prompts to install the program.
  3. When your Malwarebytes for Windows installation completes, the program opens to the Welcome to Malwarebytes screen.
  4. Click on the Get startedbutton.
  5. Click Scan to start a Threat Scan.
  6. Click Quarantine to remove the found threats.
  7. Reboot the system if prompted to complete the removal process.


Extension name examples:


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