According to Reuters, High-tech, financial services, media and/or entertainment, and power and energy companies suffered the highest intensity of cyberattacks per company in a six-month period studied by Riptech, a firm that provides security monitoring of corporate and other computer networks. High-tech, financial services, media and/or entertainment, and power and energy companies suffered the highest intensity of cyberattacks per company in a six-month period studied by Riptech, a firm that provides security monitoring of corporate and other computer networks.

On a percentage basis, most of the attacks detected were relatively benign in nature. But the number of severe attacks was still substantial, with critical and emergency-level events detected on 43 percent of the client networks, the study found. "Our findings strongly suggest that once companies connect their systems to the Internet, they are virtually guaranteed to suffer some form of attack," the report said. Average attacks per company increased by nearly 80 percent over the six months studied. Riptech's data indicates that more cyberattacks originate in the United States than in any other country. And the number of attacks that appear to come from Israel is nearly double that of any other nation based on number of Internet users. Israel leads the list of countries in terms of number of computer attacks per 10,000 Internet users, followed by Hong Kong, Thailand, South Korea, France, Turkey, Malaysia, Poland, Taiwan and Denmark, according to the study from Riptech.

"Israel is a country with pretty sophisticated warfare capabilities," that spread through the relatively computer-literate general population, said Amit Yoran, president and chief executive of Riptech, which is based in Alexandria, Virginia. For the study, Riptech investigated more than 128,000 cyberattacks found in the analysis of 5.5 billion log entries and alerts on its customer's networks between July and December 2001. The company has about 300 customers in 25 countries.

While most attacks can be traced back to what is believed to be the source country, it's possible for malicious hackers to hide their exact location, according to Yoran. The study found that attacks that appeared to originate in the United States -- nearly 30 percent of the total -- were almost triple those of the second-ranked country. But only about 3.5 attacks were made per 10,000 U.S. Internet users, compared with 26 attacks per 10,000 Internet users in Israel, the study found. Behind the United States in percentage of total attacks were South Korea, China, Germany, France, Canada, Taiwan, Italy, Great Britain and Japan.

The study found that power and energy companies were primarily targeted by cyberattackers in the Middle East while high-tech and financial services companies were targeted by Asian attackers. Of particular note was the fact that the "Code Red" and "Nimda" worms were so predominant -- accounting for about 63 percent of the malicious activity detected by Riptech -- that they were excluded from the study. "We had to pull them out or they would have completely skewed any type of analysis," said Yoran. "They were just so prevalent over that six-month period." Excluding Nimda, the attacks studied by Riptech dipped during the week following September 11 but began to rise in the third week of September, peaking in the middle of November and declining slightly in early December.

Companies with more than 500 employees suffered at least 50 percent more of the studied attacks than smaller companies, while public companies suffered about twice as many of the attacks as private and nonprofit companies. Thirty-nine percent of the attacks looked targeted, appearing to be deliberate attempts to compromise a specific system or company. "That was just mind-boggling to me," Yoran said. Yoran said the study was different from most in that it relied on actual attack data rather than surveys of network administrators or other company officials, which Yoran said are not always accurate.