Trojans accounted for 70% of all new malware between April and June 2009, and were responsible for more infections than any other type of malware over this period.

According to data compiled in the latest PandaLabs Quarterly Report, trojans were behind 34,37% of all infections detected by Panda, an increase of 2,86% with respect to the previous quarter.
Adware infection levels remained stable, accounting for 19,62% of the total.
One of the most notable findings of the report is the 6,25% drop in spyware, which now represents just 6,9% of all new malware. In contrast, adware rose dramatically over this period, from 7,54% in the previous quarter to 16,37%. This is largely due to the surge in fake antivirus applications, a type of adware that passes itself off as a legitimate security solution.
As for worms, their percentage has also risen slightly, now accounting for 4,4% of all malware. Dialers, at 4,48%, stubbornly refused to disappear despite the overriding trend for broadband instead of dial-up connections.
In terms of specific strains of malware, the number one ranked specimen in Q2 was Downloader.MDW, a Trojan designed to download other malware on to computers. The Virtumonde spyware and Rebooter.J Trojan were also among the malicious codes that caused most infections.
A worm appeared in April which used a cross-site scripting technique to infect Twitter users when they visited the profiles of other infected users. It then infected the new user’s profile to continue propagating. New variants appeared, and finally the creator's identity was revealed: one Mikey Mooney, who apparently wanted to attract users to a service competing with Twitter.
In early June, Twitter was the focus of other attacks, this time using different techniques, above all BlackHat SEO. Twitter has a feature called “Trending Topics”, which is a list of the most popular topics that appears in the interface of all Twitter users. When users select a topic through this feature, they will see all ‘tweets’ published related to this issue.
In this case, malicious users were writing tweets about the topics listed in Twitter Trends with links to malicious Web pages from which malware was downloaded.