An analysis of Internet threats by Network Box in August 2009 shows that the volume of malware, which peaked in July (when volumes increased by 300 per cent), are down again at levels seen in June (around four viruses per customer, per hour). Spam is also down slightly, averaging around 90 spam e-mails per customer, per hour (from a peak of around 120 in May).

The US continues to dominate as the main source of the world's viruses, producing 15.9 per cent of all viruses. It is followed closely by Brazil, which produces 14.5 per cent (similar levels to last month's 14.1 per cent).

Brazil continues to be the biggest source of spam, producing 11.6 per cent of all spam, followed by the US at 8.6 per cent and South Korea at 7.2 per cent.

South Korea remains the biggest source of intrusion attacks, at 17.3 per cent.

Phishing attacks also remain high, at 33 per cent of all viruses. This is down slightly from last month's 36.2 per cent, but still significantly higher than in June, when phishing attacks made up just five per cent of all viruses.