Targeted attacks intercepted by Symantec.cloud rose to 85 per day, the highest figure since March 2009 when the figure was 107 per day in the run-up to the G20 Summit held in London that year. Simultaneously, in the aftermath of the Rustock botnet takedown, global spam volumes continued to fall and decreased by 6.4 percentage points since March to 72.9 percent in April.
MessageLabs Intelligence also revealed that shortened URLs have become increasingly popular recently, being used to lure people to click on advertising links; a practice known as click-fraud.
In April, 1 in 168.6 emails contained malware and targeted attacks accounted for approximately 0.02 percent of these. This represents an increase of 10.5 percent over a period of six months. The number of targeted attacks blocked each day was approximately 77 in October 2010.
“The trend in targeted attacks suggests there may be a seasonal pattern as the number of targeted attacks always seems to be higher at this time of year,” said Paul Wood, MessageLabs Intelligence Senior Analyst, Symantec.cloud. “As the financial year draws to a close in many countries, it is also possible that the timing is perfect for cybercriminals seeking information about the financial performance of a company, and a carefully crafted attack may be just the means by which they can achieve this.”
Also known as Advanced Persistent Threats (APTs), targeted attacks are frequently delivered by email and designed to breach a specific target for the purpose of industrial espionage.
During April, MessageLabs Intelligence identified 11 automated bots operating on a popular micro-blogging service, posting messages containing shortened URLs and using a variety of techniques to bring these messages to the attention of other users. People clicking on these links are redirected to web sites containing advertising links, which in turn will generate pay-per-click revenue for those sites hosting the banner ads.
“There are a number of motivations behind enticing users to follow shortened URLs, the primary one being financial gain,” Wood said. “Although online advertising providers have worked hard to prevent Web sites from being setup purely to profit from advertising revenues, the practice is still prevalent.”
Other report highlights:
Spam: In April 2011, the global ratio of spam in email traffic from new and previously unknown bad sources decreased by 6.4% percentage points since March 2011 to 72.9% (1 in 1.37 emails).
Viruses: The global ratio of email-borne viruses in email traffic from new and previously unknown bad sources was one in 168.6 emails (0.593 percent) in April, an increase of 0.114 percentage points since March.
Endpoint threats: The most frequently blocked malware targeting endpoint devices for the last month was the W32.Sality.AE virus. This virus spreads by infecting executable files and attempts to download potentially malicious files from the Internet.
Phishing: In April, phishing activity was 1 in 242.2 emails (0.413 percent), an increase of 0.02 percentage points since March.
Web security: Analysis of web security activity shows that an average of 2,431 Web sites each day were harboring malware and other potentially unwanted programs including spyware and adware, a decrease of 18.2 percent since March 2011. Thirty three percent of malicious domains blocked were new in April, a decrease of 4.0 percentage points since March. Additionally, 22.5 percent of all web-based malware blocked was new in April, a decrease of 1.9 percentage points since last month.
- Oman became the most spammed in April with a spam rate of 81.9 percent.
- In the US 72.8 percent of email was spam and 72.7 percent in Canada and the UK.
- In The Netherlands, spam accounted for 74.1 percent of email traffic, in Germany 73 percent , 72.4 percent in Denmark and 73.6 percent in Australia.
- Spam levels in Hong Kong reached 72.4 percent and 70.3 percent in Singapore. Spam levels in Japan were 68.9 percent.
- In South Africa, spam accounted for 72.4 percent of email traffic.
- Luxembourg remained the most targeted by email-borne malware with 1 in 28.9 emails blocked as malicious in April.
- In the UK, 1 in 86.2 emails contained malware. In the US virus levels were 1 in 311.6 and 1 in 201.8 for Canada. In Germany, virus levels reached 1 in 277.5, 1 in 647.9 in Denmark and 1 in 311.2 for The Netherlands.
- In Australia, 1 in 271.3 emails were malicious and, 1 in 321.0 for Hong Kong, for Japan it was 1 in 902.9 compared with 1 in 640.0 for Singapore.
- In South Africa 1 in 68.1 emails contained malicious content.