An ingenious new trojan is hijacking PCs to send
SMS-based spam to mobile phones.
After a PC has been infected, the Delf-HA trojan contacts a
website for details on which spam campaign to run and then randomly
generates a series of Russian mobile numbers beginning with the
prefix +7921 or +7911. It uses the send e-mail function of a number
of Russian mobile network websites to deliver the mail sent from
the infected machines.
That many of the mobile numbers will not have been allocated to
customers is of no consequence as enough real ones can be targeted
randomly. The contents of the spam are thought to vary but one
message shown to Techworld promoted the download of MP3 music files
from a named Russian website.
Although Delf-HA targets only Russian mobile networks, experts
have warned that the same technique could be used to send spam to
subscribers of networks in other countries.
"Now SMS spammers are taking a leaf out of the book of e-mail
spammers, and using unprotected innocent PCs to pass on their
unwanted messages," said Graham Cluley of antivirus supplier
Sophos.
Spam is not a new phenomenon on mobiles but volumes remain low
compared with PC-based e-mail. Delf-HA could signal a depressing
turning point.
To date, most of the concern has centred around the possibility
of viruses such as Cabir infecting mobiles themselves. Nokia also
announced in the summer that it would offer antivirus software for
its 6670 smartphone.
John Dunn writes for Techworld