Malware packers have gained even more popularity in the month of April, as three of the positions on BitDefender’s April 2008 Top Ten Malware list are occupied with malware packed by such software. According to BitDefender Labs, the three are all packed with the same type of packer (NSAnti) which has caused problems in previous months.
Straightforward packers aren’t the only tools used for this purpose. The fourth position on the list is a sophisticated malware loader, dubbed by BitDefender researchers as “Loader.N.” Loader.N runs decrypts and enables two other packed pieces of malware (a Trojan, Kobcka and a Trojan, Downloader.Agent) which transforms the infected machine into a spam relay.
The rest of the top ten is, yet again, pretty well-populated with mass mailer viruses, with the Cutwail Trojan, another tool turning machines into spam bots, appearing in the 6th position.
BitDefender’s April 2008 Top 10 malware list includes: