The infamous Kido or Conficker – aka Win32.Worm Downadup.Gen, which last week passed the first anniversary of its trigger date – ranks second with a score of 6.19%.
According to BitDefender, once again this has been a fairly constant piece of malware, which exploits a well-known Windows vulnerability but, the IT security vendor notes, in order to get rid of the electronic pest, users need only update their operating system and their locally installed anti-malware software.
Third in BitDefender's March list is Exploit.PDF-JS.Gen, which manipulates Adobe PDF Reader's Javascript engine with the sole purpose of executing malicious code on a users' PC.
File infectors, meanwhile, are represented by Win32.Sality.OG, which BitDefender reports as coming in fourth position.
Shielded by a polymorphic code, the IT security vendor reports that the Sality family is extremely difficult to detect and remove. And in addition, BitDefender says that the rootkit component of the virus tries to disable various antivirus applications installed on the infected system.
Ranking fifth is Trojan.JS.Downloader.BIO. This is a Javascript inserted into legitimate webpages using SQL injection techniques targeting only those websites built with ASP.Net, the Microsoft web application framework.
The interesting aspect of this trojan, says BitDefender, is that it creates cookies with miscellaneous pieces of information about the victim – such as browsing habits and timestamps – and then sends them to a China-based website.