Infected programs will either grow by 1090 or 1134 bytes, depending on their previous size. The virus activates on October 23rd of any year, displaying the message "Karin hat GEBURTSTAG".
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
More information on 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 information.