F-Secure shares a weblog which is one of my favorite sites to check for breaking developments. The following table shows some of the largest virus families where multiple variants have been constantly created (with Agobot as their top entry with over 450 entires).
http://www.f-secure.com/weblog/
LARGEST VIRUS FAMILIES (as noted by F-Secure)
| FAMILY NAME |
LAST VARIANT |
TYPE |
| Agobot |
RO |
Backdoor |
| CAP |
JM |
Word Macro |
| Delf |
MV |
Backdoor |
| Jerusalem.1808 |
FV |
File infector |
| Laroux |
OU |
Excel Macro |
| Loveletter |
CZ |
Word Macro |
| Marker |
LA |
Word Macro |
| Npad |
KB |
Word Macro |
| SDBot |
KL |
Backdoor |
| Stoned |
EV |
Boot sector |
| Thus |
GP |
Word Macro |
| Wazzu |
HM |
Word Macro |