The total number of reports in 2001 counted 24,261, which was over the double of the same in 2000. It was the highest number we have ever recorded.

Even though the number of reports increased rapidly, the percentage of the actual infection remained 19%. Which shows that the appropriate measurements such as applying anti-virus software have been common.

"Detection only"; Viruses were discovered by such as anti-virus software so that PCs were protected to be infected in advance.

The following table shows the number of reports sorted by reporting body.　The rate for "Individual user" has rapidly increased.

	2000				2001
	Number of report		Number of actual infection		Number of report		Number of actual infection
General corporate user	9,975	89.8 %	1,480	14.8 %	17,332	71.4 %	2,793	16.1 %
Individual user	920	8.3 %	601	65.3 %	5,643	23.2 %	1,479	26.2 %
Education/Research Institute	214	1.9 %	101	47.2 %	1,286	5.3 %	404	31.4 %
	11,109		2,182 (19.6%)		24,261		4,676 (19.3%)

a) There were 112 kinds of viruses reported in 2001. Among those, 22 kinds (11,712 reports) of the viruses were reported for the first time. Although many viruses that misuse email systems were reported followed by the year 2000, it is noticeable that the number of reports of the viruses, which misuse vulnerabilities and propagate themselves such as W32/Aliz and W32/Badtrans (a variant), have rapidly increased in 2001.

	2000		2001		Major viruses
Viruses that misuse email systems	6,692	60.2 %	14,263	58.8 %	Hybris、Sircam、MTX
Viruses that misuse vulner-abilities	507	4.6 %	6,338	26.1 %	Badtrans、Aliz、Nimda
Macro virus	3,393	30.5 %	2,812	11.6 %	Laroux、Divi
Other viruses	528	4.7 %	848	3.5 %	QAZ、Funlove
Total number	11,120		24,261

Note: Those viruses that misuse both email systems and vulnerabilities such as Nimda are sorted into the viruses that misuse vulnerabilities. And Macro virus includes Melissa and Prilissa. （There are often more than one virus of reports in a report so that the total number is not the same number as the total reports.） Name of the major virus reported in the month is shown in a mark of.

Properties of viruses that misuse vulnerabilities.

• It will infect once the infected email is previewed with Microsoft’s OutlookExpress.
  (Badtrans (a variant), Aliz and Nimda)
• It will infect once you see the body of the infected email with Microsoft’s Outlook or OutlookExpress.
  (Badtrans (a variant), Aliz and Nimda)
• It will infect once you surf the infected Web page with Microsoft’s InternetExplorer.
  (Nimda)

b) Virus name
The reported virus that got the highest number was Hybris, followed by Badtrans which received more than 1000 reports in a month (2701 reports in December), Sircam (1257 reports in August) and Aliz (1020 reports in November）. It shows that the viruses that misuse email systems and vulnerabilities propagete themselves so quickly and infectively.

Virus name	2000	2001	Misuse email systems	Misuse vulner-abilities	Macro virus
W32/ Hybris	181	4,915	*
W32/ Badtrans (*)	-	3,281	*	*
W32/ Sircam	-	3,017	*
W32/ MTX	2,136	2,934	*
W32/ Magistr	-	1,894	*
W32/ Aliz	-	1,402	*	*
XM/ Laroux	1,041	1,034			*
W32/ Nimda	-	891	*	*
X97M/ Divi	541	584			*
W32/ Navidad	1,202	477	*
Other viruses	6,019	3,832
Total number	11,120	24,361

(*) The number for W32/Badtrans includes its variant.

IPA Security Center（IPA/ISEC)
(ISEC: Information technology SEcurity Center)
Phone: 03-5978-7508 FAX:03-5978-7518  E-mail:
Emergency call: 03-5978-7509  URL: http://www.ipa.go.jp/security/