Security experts at the security firm discovered that currently nine of ten spam emails contain a URL in the message. In May 2010, out of all domains discovered in spam URLs, 5% indicated to genuine websites. The top four domain names used most commonly in spam URLs were found belonging to popular websites used for blogging, file sharing, social networking as well as harbor other types of user-generated content.

Paul Wood, MessageLabs Intelligence Senior Analyst, said regarding these findings that domains of popular sites are recycled and used repeatedly in comparison of disposable domains that are used for quite a shorter time period and are never used again. This is probably because acquiring them requires some work: in case of authentic domains, CAPTCHAs are required to be solved so as to create accounts in large numbers to be used by spammers, as per the news published by marketwatch.com on May 26, 2010.

Reportedly, Rustock botnet uses the highest number of disposable domains, while, on the other hand, Storm is the sole botnet to use greater number of legitimate domains than the disposable ones. It is noteworthy that Storm has recently made a comeback into the spamming arena.

Apart from this, Symantec found that spam emanating from Kenya, Uganda and Rwanda has increased significantly, reported zdnet.co.uk on May 27, 2010.

The latest study also reveals that one in 237.1 emails (or 0.42%) found across the world in May 2010 represented phishing email, representing an increase of 0.2 percentage points over April 2010. Phishing emails accounted for 80.6% of total email-borne threats, 10.3 percentage points up from April 2010.

Lastly, the world ratio of email-borne viruses in total email traffic, both from fresh and existing sources, stood at one in 211.6 emails (0.473%) in May 2010, indicating an increase of 0.18 percentage points over the previous month. In addition to this, 22.6% of email-borne malware included links to malicious sites, a decline of 6.3 percentage points from April 2010.