Can Online Scanner delete my files or corrupt the system during remediation?

Online Scanner automatically quarantines everything that it removes. To see quarantined items, run Online Scanner again and select View quarantine.

Before remediation, Online Scanner creates a system restore point named "F-Secure Malware Removal". If anything bad happens, you can always roll back using System Recovery. If the System Recovery is not accessible (for example, when the system doesn't boot), it can be reverted back to bootable state by F-Secure Rescue Media: http://www.f-secure.com/en/web/labs_global/antibot /rescue-media.