Note that Malwarebytes Anti-Malware Portable is a free tool, but some features may require a license or subscription for full functionality. Be sure to review the terms and conditions before use.
Malwarebytes does not prominently offer a free, standalone portable version on their homepage. However, legitimate portable versions are available through: Malwarebytes Anti-malware Portable
Once you have the portable version on your USB drive, follow this workflow for maximum effectiveness. Note that Malwarebytes Anti-Malware Portable is a free
Portable security tools offer several advantages for emergency recovery: Malwarebytes Anti-malware Portable