The reported number for the computer virus for the first half (January to June) in 2009 was 9,282.  Following graph (Chart 1) shows the reported number for every 6 month summarized by IPA.

As it shown, they are tending to decrease for recent years. Upon comparing the number in the first half of 2006 and the first half of 2009, it is apparent that they are decreased to about 40% of their peak period (i.e., for here, the one in the first half of 2006) from 23,828 to 9,282. This may be the cause that the bulk mail-distribution type of virus which targets to the Internet users in every level had not emerged/spread during the subjected periods so that the reports itself was lessened, accordingly.

Chart 1: Number of Report

According to the shift in detection number of virus over the past year, they are tending to decrease as with the reported number of virus as well.  The main cause of such decrease can be the decrease of the detection number of W32/Netsky, the worst reported virus ever.

However, W32/Autorun in October and November 2008, and W32/Downad in April 2009 were drastically increased in their detection number respectively. W32/Autorun is the typical virus which enlarges infection via an USB memory and actually enlarged infection in that period. As with the W32/downad, there emerged its variant which carries such function to enlarge infection via an USB memory and caused certain damage.

In this way, there is a potential that the virus which carries another infection path (s) may be rapidly expanded: accordingly, be sure to conduct your anti-virus measures continually.

Chart 2: Detection Number of Virus

According to the reported number of virus filed with IPA, the reported number for W32/Netsky is continually overwhelming to others. In that circumstances, there significantly increased the reports relevant to W32/Autorun which enlarges infection via an USB memory in the last part of 2008. Even the handy device, USB memory; be sure to recognize that there is certain risk that some virus may be hidden.

To prevent from infection damage by these viruses, it is important to apply modification program (s), leverage security software, be cautious of handling attachment file to e-mail as well as to conduct certain security measures for USB memory regularly.

Chart 3: Reported Number by Virus

Information-Technology Promotion Agency, Security Center
Hanamura/Kagaya/Ooura
Tel:+81-3-5978-7527
Fax:+81-3-5978-7518
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