86 Percent of All Emails Sent in September Were Spam

According to a report from antivirus giant Symantec, spam messages amounted for over 86% of all emails sent last month. Meanwhile, the number of emails distributing malware has increased nine times since August and now represents 1.3% of all spam.

Symantec's monthly State of Spam report (PDF) reveals that spam traffic is slowly decreasing, while remaining considerably higher than what it was last year during the same period. This month's average number of 86% is lower by 1% than it was in August and by 3% than in July. However, it is higher by 8% than what was registered in September 2008.

One worrying aspect of the past's month spam activity is the consistent increase in emails containing malware. "In September 2009, an average of 1.3 percent of all spam messages contained malware. When compared with August 2009, this equates to a nine fold increase," the report reads. This sort of spam actually hit the 4.5% value at one point last month.

Because of this malicious activity, the average email message size has also increased by 5% for messages between 5 KB and 10 KB and also those over 10 KB. In addition, subjects such as "Notice of Underreported Income," "Thank you for setting the order No.475456" or "Your order," which are common for emails with malicious attachments, have made it to high positions in the top 10.

When it comes to spam categories, messages advertising Internet and computer-related services dominated and accounted for over 32% of junk email. General goods and services spam took second place with 19% distribution rate, while unsolicited financial messages came in third with 17%. None of the other spam categories, such as 419 scams, health, fraud, leisure or adult, scored over 10%.

The United States remains the biggest source of spam, with a whooping 25% of such emails originating from this country. Brazil occupies the second position, but is far behind the US with only 12%. India and South Korea are each responsible for sending 4% of junk emails. Russia is back again in the top 10 on the last position with 2%, after not making the list in July and August.