Andrew Gordon, managed services architect at anti-virus software vendor, Trend Micro, said it had been seeing a real bounce-back of Klez.h and some of the other Klez variants.
Klez.h is now ranked number one on its worldwide list of top 10 viruses, having surpassed SirCam.
At time of going to press, Trend Micro's statistics showed more than 116,000 incidents of Klez.h over the past 30 days.
-One thing which concerns us is the longevity," Gordon said. -With previous viruses they haven't been as intelligent as Klez."
According to Gordon, this means that the human aspect of protection isn't as effective when there's a huge list of possible subject lines. -No one can remember 45 different subject texts of things not to open," he said.
However, Gordon added that it was hard to tell how much damage was still occurring, or whether activity was due to e-mail users patching, detecting and cleaning.
This Klez viris is an extreme nuisance and
extremely distruptive to all users and businesses.
The are users now not wanting to even use e-mail
due to the multitude of viruses existing in their
mailbox(es). Sooner or later viruses will kill
the most effective communication method available:
e-mail. I for one am extremely tired of these
Klez generated e-mails as it is burdening business
and making users to avoid e-mail. The downfall of
e-mail and other effective communication methods
may be the result from these viruses and trojans.