Mytob was flavor of the month in June. We had Mytob with worm and bot capabilities, Mytob without bot capabilities, Mytob packed with one, two or three packers and so forth. In short, Mytob variants dominated email traffic this month. Mytob.c maintained the leading position it occupied in both April and May making NetSky.q, the worm which occupied first place the longest in 2004, unlikely to regain first place. Interestingly, both worms have lost points in terms of overall percentage of traffic: the losses are directly in proportion to the increase in the percentage of other malicious programs.
The endless Mytobs left so little space for other worms that all 6 newcomers to the ratings are members of this prolific family. Some of these new worms are simple worms, without botnet capability. This is a change from the recent trend where virus writers include botnet capability in most new worms. Surprisingly, Zafi.d jumped from ninth to third place - the second largest increase in June. This unexpected surge does not fit into the general pattern of Mytob domination. On the other hand, Mytob.be, a new variant which took fourth place is entirely explicable given the plethora of Mytobs this month.