Spam in email traffic rose 4.2 percent in second quarter of 2013 to 70.7 percent from the first quarter, said Kaspersky Lab.
Phishing emails in global mail traffic fell by 0.0016 percent to 0.0024 percent.
The number of attacks launched against social networks fell by 3.3 percent, and attacks against financial organizations increased 1.2 percent, pushing that category into second place in the ratings.
Many emails with malicious attachments were addressed to corporate users this past quarter. These emails were disguised as auto-replies, i.e., delivery failure notifications, or notifications of the arrival of an email, fax, or scan.
Kaspersky Lab says malicious users expect corporate employees to skim over the details, assume the email is legitimate and open the attachment — releasing a malicious program.
One unusual feature in Q2 was the distribution of eCards with malicious attachments.
The countries which most actively send spam are the same as before, although their percentages have changed slightly: China is down by 1.2 percent, the US is down by 0.9 percent, and South Korea’s percentage is lower by 3 percent.
The majority of spam emails are still very small, weighing in at under 1Kb. Over the second quarter there were 4.8 percent more of these small emails, and they made up 73.8 percent of all spam mails.
The amount of malicious attachments in the second quarter was 1 percent lower than in the first, coming to 2.3 percent of all mail traffic. Among the threats spread by email, the most prevalent families are those designed to steal data to access user accounts (usernames and passwords), particularly for online banking services.
There were few changes in the range of organizations targeted by phishing attacks in the second quarter. The number of attacks launched against social networks fell by 3.3 percent, and the percentage of attacks against financial organizations increased by 1.2 percent, pushing that category into second place in the ratings.