Trojan:HTML/Browlock is ransomware that prevents users from accessing the infected machine's Desktop; it then demands payment, supposedly for either possession of illegal material or usage of illegal software.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
For more information, see Removing 'Police-themed' Ransomware.
More information on the scanning and removal options available in your F-Secure product can be found in the Help Center.
You may also refer to the Knowledge Base on the F-Secure Community site for more assistance.
Trojan:HTML/Browlock has been reported to target users in multiple countries, including the United States, the United Kingdom and Canada. Typically, it will display a 'lock screen' purportedly from a local or federal law enforcement authority, claiming that the machine has been locked and encrypted due to 'illegal activities'. A 'fine' is then demanded to restore the system.
This malware was also covered in our Labs Weblog blogpost:
A lock screen used by one Browlock variant is shown below: