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Repacking malware is currently the preferred technique

BUCHAREST, Romania – May 09, 2008 – Malware packers seem to have become the technique of choice for cyber crooks according to BitDefender®, a global provider of award-winning antivirus software and data security solutions. Three of the positions on BitDefender’s April 2008 Top Ten Malware list are occupied with malware using the same type of packer (NSAnti) – a device which has caused problems in previous months.

"It seems repacking malware to attempt avoiding detection, rather than spending time and energy writing new viruses from scratch is a technique that's here to stay," said Sorin Dudea, Head of BitDefender AV Research.

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.” This 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 loader serves two purposes: the encryption prevents antivirus software from detecting the payload in transit, while the unpacking and loading part ensures that at no point does the payload get written to disk – eliminating another inception point," Dudea explained. "Of course, the exercise is pointless, as we can still detect the decryptor itself."

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:

1. Packer.Malware.NSAnti.AD 33.71%
2. Win32.Netsky.P@mm 7.48%
3. Win32.Worm.Sohanad.NAW 4.56%
4. Packer.Malware.NSAnti.AG 2.86%
5. Trojan.Loader.N 2.25%
6. Trojan.Dropper.Cutwail.F 2.04%
7. Win32.Netsky.AA@mm 1.98%
8. Win32.NetSky.D@mm 1.98%
9. Packer.Malware.NSAnti.Z 1.87%
10. Win32.Nyxem.E@mm 1.65%
11. OTHERS 39.62%

About BitDefender®
BitDefender is the creator of one of the industry's fastest and most effective lines of internationally certified security software. Since our inception in 2001, BitDefender has continued to raise the bar and set new standards in proactive threat prevention. Every day, BitDefender protects tens of millions of home and corporate users across the globe—giving them the peace of mind of knowing that their digital experiences will be secure. BitDefender solutions are distributed by a global network of value-added distribution and reseller partners in more than 100 countries worldwide. More information is available at

Contacts UK

Mike Ottewell
MJO Associates for BitDefender UK
Tel: 01538 361217

Nick Billington
BitDefender Country Manager (UK and Ireland)
Tel: 08451305096
Fax:- 0845 130 5069

This press release was distributed by ResponseSource Press Release Wire on behalf of MJO Associates in the following categories: Consumer Technology, Personal Finance, Business & Finance, Computing & Telecoms, for more information visit