The volume of targeted cyber-crime attacks has reached its highest ever level, a security firm has claimed.

Network Box said that small firms are the most vulnerable to online attack as they have the lowest levels of IT security protection in place.

The vendor noted that, although virus levels are dropping month on month and made up just 30 per cent of all malware in June, this danger is being replaced with a "much more sinister threat".

Cyber-criminals are using worms, Trojans and spyware, which now make up to 70 per cent of all malware, to target the most vulnerable sectors of PC users: smaller businesses and home users who do not have sophisticated antivirus packages.

Network Box cited its own research as showing that SMEs are "wide open to network attack".

It said that 63 per cent of such firms have no protection against phishing attacks, 69 per cent do not filter web content to protect themselves from employees downloading harmful content, and 50 per cent have no protection against spyware.

Simon Heron, technical director at Network Box, said: "Techniques that have been used in the past to target big businesses have been revised to target those most vulnerable and therefore the most likely to respond.

"Robbing a small amount of money from a large number of individuals is proving more lucrative than robbing a large sum from a few."

The key trend of 2006, according to the firm, is the growing sophistication of techniques used to target vulnerable individuals.

The botnet has come into its own in the first half of the year, with botnet 'masters' continuing to hone and improve techniques to enslave business PCs. Cells of botnets are getting smaller and therefore almost undetectable, the research added.

The increase in botnets has also led to a marked increase in the number and sophistication of phishing attacks.

Such attacks have developed to include spear phishing in which an email targeted at an individual appears to come from a trusted source, e.g. from within a company.
Network Box warned that the combination of botnets which allow scammers to generate huge numbers of emails, and targeted spear phishing techniques that allow those emails to appear personal to the individual, results in an effective revenue generator for cyber-criminals.

"Botnets can be very damaging to the businesses they are exploiting as well as to their end targets," said Heron.

"If a business becomes infected and unwittingly sends out spam containing phishing links or other malware it will end up blacklisted by anti-virus filters and therefore unable to do business online. The damage can be difficult to repair."