Internet attacks against public and private organizations around the world leapt 28 percent in the past six months, with most targeting technology, financial services and power companies, according to an industry report due out today.

The report, conducted by the Internet security firm Riptech Inc. of Alexandria, indicated that the information backbone upon which many countries rely remains vulnerable to cyber-attacks.

"The Internet is still an extremely dangerous place and attack activity is increasing at a significant pace," said Elad Yoran, Riptech's executive vice president.

The study tracked cyber-security breaches at more than 400 organizations that Riptech monitors, including government agencies, private companies and nonprofit groups, and found more than 180,000 successful Internet attacks from January to June. There were only 160,000 attacks against the same organizations during the previous six months.

The report's most startling findings point to the growing attraction of large, critical service providers to hackers worldwide. Seventy percent of the power and energy companies under review suffered at least one severe attack during the first six months of 2002, according to the report, compared with 57 percent for the previous six-month period. There were 1,280 crimes against such firms, compared with 667 attacks on health-care companies and 617 against those in manufacturing.

"In the hacker community, you are going to score more points for hitting bigger companies," said Dorothy Denning, a Georgetown University professor who specializes in security and information warfare. "There is also an economic gain to going after the large financial services targets -- they have the money."

Those who prey on computer networks are not spread uniformly around the world. About 80 percent of cyber-crimes were launched from the same 10 countries, the report said. More than 40 percent of the 180,000 attacks were conducted through computers in the United States. The report does not indicate where the victims of the attacks were located.

Cyber-attackers appear to be busiest during the five-day business week. The report shows attacks occurred most frequently Monday through Friday and dropped off dramatically on the weekend when many of the world's industries are closed. The most popular day for attacks, Riptech found, was Wednesday.

The report shows no increased Internet threats from countries that the U.S. government describes as sponsors of terror. But that does not mean people in these states are not perpetrating cyber-crimes, the report said.

Tracking cyber-attacks inside Iraq, North Korea, Syria and Libya is hampered by "primitive or non-existent Internet infrastructures" there, the report stated. It is possible terrorists based in these countries are launching attacks, Riptech's Yoran said, likely through host computers located in other nations.

"But we have no way of finding out," he said. "They can use our computers here in the U.S. to attack other U.S. companies."

Though the vast majority of attacks occurred in country's with wide Internet access, hackers also are active in nations where the online infrastructure is fledgling. Among such countries, the greatest number of attacks originated in Kuwait, followed by Iran, according to the report. But the actual number of security breaches begun in both nations remains extremely small, less than 1 percent of all attacks calculated in the report.