ANNOUNCEMENT PURSUANT TO SECURITIES ACT CHAPTER 2, SECTION 10

| Source: F-Secure Oyj F-Secure Oyj 

F-SECURE CORPORATION          STOCK EXCHANGE ANNOUNCEMENT                       
                              Translation from Finnish                          
                              April 4, 2008 at 16.10 


ANNOUNCEMENT PURSUANT TO SECURITIES ACT CHAPTER 2, SECTION 10                   

F-Secure Corporation has been informed today by Osuuspankkikeskus Osk (identity 
0242522-1) that OPK's holding and voting rights will go over one-twentieth      
(1/20).                                                                         
                                                                                

1. The company: F-Secure Corporation                                            

2. The date of change in holding: April 4, 2008                                 

3. Exact proportion of voting rights and share capital in                       
F-Secure Corporation:                                                           

Totally 7,934,274 shares; 5.12% of voting rights and share capital.             

4. Shareholder:                                                                 

Shareholders and their share of voting rights and of share capital.             


                                          Shares   of capital   of votes        

OP-Rahastoyhtiön hallinnoimat rahastot, Y-tunnus 0743962-2                      

Pohjola Vakuutus Oy, 1458359-3            225.000    0,145 %    0,145 %         
A-Vakuutus Oy, 1715947-2                   25.000    0,016 %    0,016 %         
OP-Delta, 1102395-3                     2.994.930    1,931 %    1,931 %         
OP-Teknologia , 1601124-9                  50.763    0,033 %    0,033 %         
OP-Focus , 1753298-6                    1.244.424    0,802 %    0,802 %         
OP-Pohjola Pienyhtiöt, 1960678-2          650.000    0,419 %    0,419 %         
OP-Suomi Pienyhtiöt  1753300-6          2.744.157    1,769 %    1,769 %         

TOTALLY                                 7.934.274    5,115 %    5,115 %         


F-Secure Corporation                                                            

Kimmo Alkio                                                                     
President & CEO                                                                 

Additional information:                                                         

F-Secure Corporation                                                            
Taneli Virtanen, CFO                             tel.358 9 2520 5655            

DISTRIBUTION                                                                    
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