E-mail Leading Cause Of Computer Viruses

A study just released by the National Computer Security Association suggests that computer viruses are getting bigger and better at what they do--particularly when targeting business computers. The rate of computer virus infection in corporate America has nearly tripled in the past year, the study found, despite the fact that the use of anti-virus software has grown from 60 percent of the machines surveyed by NCSA in 1996 to 73 percent in 1997. Electronic mail is now one of the leading methods of virus transmission.

The study found that virtually all mid- and large-sized organizations in North America experienced at least one computer virus infection firsthand. Based on the information, NCSA predicted that approximately 40 percent of all computers used in the surveyed companies would experience a virus infection within a year. Macro viruses carried in common word processing documents and spreadsheets were the biggest problem, representing 80 percent of all infections. Comparing these figures to the 49 percent rate a year ago, the NCSA study indicated the instances of macro virus infection had doubled about every four months over the past year. The number one virus encountered was the WordConcept, which caused almost half of all infections reported. The Wazzu virus, another macro virus that infects Word documents, was responsible for about one-fifth of all infections.

Of the 300 survey respondents, representing more than 700,000 desktop computers and 24,000 servers, the infection rate was found to be about 33 of 1,000 machines infected in any given month, and 406 of 1,000 machines infected in a given year. This is a significant increase from 1996, when the chance of experiencing a computer virus was about 10 out of every 1,000 PCs per month. While the survey respondents blamed both disks brought from employees' homes and Internet/e-mail usage as the main sources of virus infection, electronic mail was the leading cause of macro virus infection.

"Macro viruses are incredibly successful viruses," said Eva Chen, president and chief technology officer for Trend Micro, one of the corporate sponsors of the study. "Because they hitchhike on document and spreadsheet files, they can travel both on floppy disks and across computer networks as attachments to electronic mail. Then they spread quickly by taking advantage of email, groupware, and Internet traffic." The surge in virus infection, Chen said, results from the fact that "computer users are used to scanning disks, but many have not updated their anti-virus policies or software to prepare for the threat from email attachments or Internet traffic.

According to the survey, respondents thought that 45 percent of their most recent virus incidents began with either a download (19 percent) or as an email attachment (26 percent).

National Computer Security Association: http://www.ncsa.com/


The above article originally appeared in Internet->Bullet April 16, 1997, Vol. 2, No. 32; published by Kent Information Services, Inc., http://www.kentis.com/bullet/jcbs.htm.