Spam mail traffic has decreased 2.8% during the third quarter of this year compared to corresponding quarter in 2011 with average of 71.5%, according an analysis by anti-virus firm Kaspersky Lab.
The analysis however revealed that there is a significant increase in the share of malicious mailings – from 3% to 3.9%.
The decrease in spam flow could due to traditional business slowdown in summer, the report added.
Slowdown in the spam mailing could also because of the gradual shift of advertising messages from email to other mediums like banner ads, social media, coupon services, and contextual advertising.
During the quarter there was a slight increase in spam flow post-vacation in September, but the overall trend during the period witnessed a decreased trend.
Kaspersky Lab analysis also found that cybercriminals tried to disguise the spam mails as official notifications.
Most of the fake mails sent during the period were allegedly sent from hosting providers, banking systems, social networks, online stores and various other services.
Among the regions, Asia stood at the top for being responsible for sending almost half of all spam mailings throughout the world (49.50%), North American stood second, being the source of 27% of spam mails.
Western Europe (6.86%) overtook Eastern Europe (3.64%) and took fourth place, and Latin America (7.34%) stood third in the list.
Kaspersky Lab Content Analysis & Research head Darya Gudkova said the migration of advertisers from spam to other venues is due in part to the increasing criminalization of spam, with a large number of advertisements for prohibited goods, as well as fraudulent and malicious emails.
"Over the past year, Kaspersky Lab experts have observed two trends in parallel: a decrease in the percentage of spam and a slight rise in the percentage of malicious mailings," Gudkova said
"More likely than not, both trends will continue, as the percentage of spam is on the decline due to the migration of advertisers of legitimate goods and services to other venues."