28 January 2001 Computer attacks rose sharply in the last six months of 2001 and particular companies are being repeatedly singled out for attack, according to a report by IT security specialist Riptech.

Riptech monitors computer systems for hostile activity on behalf of corporate customers. It says that the number of attacks against its clients increased 79% between July and December 2001.

Of these, about 39% appeared to be targeted at specific organisations, says Riptech. Analysis of the log files on the remainder of attacks suggest that they were likely to be “opportunist” attacks, in which hackers use automated scanning tools to try and identify systems with ‘weak spots’.

Among Riptech’s clients, power and energy companies suffered an unusually high rate of attacks. And, while many of these appear to have originated from the Middle East, the study fails to prove a direct link to the events of 11 September.

Riptech recorded 128,678 attacks during the period. Attack activity fell immediately after 11 September, but began to rise steadily about two weeks later, rising throughout the Autumn before declining in late December. Around 1% of the attacks posed what Riptech describes as a “severe and immediate” threat to its clients.

The US was by far the largest source of attacks, accounting for around 30% of the total, followed by South Korea, China, Germany and France. However, on a per capita basis – calculated using the number of Internet users in each country – Riptech found that the highest proportion of attacks came from Israel, including Palestinian-controlled territories.