Threat: RTF Files / The Kaspersky Malware Award .

Nobody knows malware better than the people who fight it. The people at Kaspersky know it so well that they have designated some malware samples as being the biggest, best, or worst in various ways, for May 2007. So, here's to the winners! Congratulations, you tremendous jerks.

Greediest Trojan Horse Targeting Banks
Trojan-Spy.Win32.Banker.aqu, a modification that targets 87 banks simultaneously.

Stealthiest Malicious Program
Backdoor.Win32.Hupigon.rc, packed ten times with a whole range of packers. This didn't save the backdoor from detection.

Smallest Malicious Program
Trojan.DOS.DiskEraser.b, though only 9 bytes large, is smart enough to delete data from a drive.

Biggest Malicious Program
Trojan.Win32.KillFiles.ki, the most space-hungry malicious program in May. This file-deleting Trojan weighs in at a whopping 247MB. Interestingly enough, May's smallest and largest programs both have the same malicious payload?but the difference in size is remarkable.

Most Malicious Program
Backdoor.Win32.Agobot.afy, which deletes antivirus programs using a variety of methods.

Most Common Malicious Program in E-mail Traffic
Email-Worm.Win32.Netsky.t. Despite being an old-timer, this worm is still causing major damage, accounting for over 15 percent of all malicious e-mail traffic in May 2007.

Most Common Trojan Family
The winner of this category this month is the Backdoor.Win32.Rbot family, with 454 modifications in the course of just one month.

Most common virus/worm family
The Warezov family once again took this title. A total of 78 different variants of it were detected in May, up from 72 in April.