Only 8.4% of email that reached companies in 2008 was non-malicious

PandaLabs revealed the results from its analysis on 430 million email messages from 2008 and discovered that only 8.4 percent of messages that reached companies were legitimate. Some 89.88 percent of messages were spam, while 1.11 percent were infected with some type of malware.

Only January 2008 witnessed levels of spam below 80 percent. The amount of spam fluctuated throughout the year, peaking in the second quarter at 94.27 percent of all mail reaching companies.

With respect to infected messages in 2008, the Netsky.P worm was the most frequently detected malicious code. This type of malware activates automatically when users view the infected message through the Microsoft Office Outlook preview pane. It does this by exploiting a vulnerability in Internet Explorer that allows automatic execution of email attachments.

The exploit of this vulnerability was detected by PandaLabs as Exploit/iFrame and was the third most frequently detected type of malware in emails by TrustLayer Mail.

The Rukap.G backdoor Trojan, designed to allow attackers to take control of a computer, and the Dadobra.Bl Trojan were also among the most prevalent malicious code.

Much of this spam was circulated by the extensive network of zombie computers controlled by cyber-crooks. A zombie is a computer infected by a bot, a type of malware allowing cyber criminals to control infected systems. Frequently, these computers are used as a network to drive malicious actions such as the sending of spam. Just in the last three months of the year, 301,000 zombie computers were being put into action every day.