Stonesoft - Company Announcement

ADVANCE INFORMATION ON NET SALES AND PRODUCT SALES DURING THE THIRD QUARTER: STRONG GROWTH

Stonesoft Corporation Stock Exchange Release October 3, 2011 at 1.15 p.m.

Net sales grew by approximately 40%, product sales by approximately 60%

Based on preliminary data, the net sales of Stonesoft Corporation in the third
quarter were approximately MEUR 8.0 (5.6) and grew by approximately 40 %
compared to the corresponding period in the previous year.

The company's product sales were approximately MEUR 4.7 (2.9) and grew by
approximately 60% compared to the corresponding period in the previous year.

Stonesoft has in its interim report published on 12 August 2011, based on
reasons announced at that time, estimated that advanced evasion techniques will
open new business opportunities for the company, have a positive effect on its
net sales and profitability and strengthen its competitiveness and market
position as general understanding and knowledge about advanced evasion
techniques grow. In 2011, Stonesoft aims for faster-than-market growth of net
sales and improved profitability. The now finalized preliminary data do not
change this previous announcement."We are very pleased with the strong growth of the product sales and net sales
during the third quarter of the year as well as with the fact that we have been
able to grow our market share in spite of this generally unstable market
situation", said Ilkka Hiidenheimo, CEO of Stonesoft Corporation.

The presented advance information is unaudited and it is not based on a
financial report approved by the Board of Directors.

Stonesoft Corporation will issue its interim report for January-September as
previously announced on Friday 21 October, 2011. A press conference for the
media, analysts and investors will be held on 21 October, 2011 at 10.30 am at
the Stonesoft headquarters, street address Itälahdenkatu 22 A, 00210 Helsinki.

Stonesoft Corporation
Ilkka Hiidenheimo
Chief Executive Officer

For further information, please contact:
CFO Mikael Nyberg, Stonesoft Corporation
Tel. +358 9 47 67 11

Distribution:
NASDAQ OMX Helsinki Ltd
www.stonesoft.com

[HUG#1551552]

Attachments:

ADVANCE INFORMATION ON NET SALES AND PRODUCT SALES DURING Q3.pdf