The number of phishing attacks launched against the
customers of online banks and retailers has increased dramatically,
according to research by industry association the Anti-phishing
Working Group.
Criminal groups are using backdoors to computer systems left by
viruses and worms to create networks of up to 1,000 PCs capable of
launching simultaneous fraudulent e-mail campaigns, said the
group.
The tactic led to a dramatic increase in the number of active
phishing sites, which more than doubled from 540 in September to
1,140 in October.
"For the professional phishing groups, it is a big escalation.
There are a small number of professional groups that have upped the
game.
"Instead of having eight servers sending out an attack, we are
seeing 1,000," said David Jevans, chairman of the Anti-phishing
Working Group.
The escalation has prompted banks to take the problem more
seriously after a period of denial, he said. More banks are signing
up to commercial take-down services, which allow them to remove
illegal phishing sites when they are discovered.
Computer Weekly revealed last week that banks are evaluating a
range of defensive technologies including browser plug-ins to
identify phishing e-mails.
But phishers are adopting increasingly sophisticated techniques to
evade detection, the research has shown.
Phishers might use infected PCs to create up to 50 simultaneous
phishing websites, hosted by different ISPs in different countries,
said Jevans.
It can take up to a month to take down rogue sites, leaving bank
customers exposed for a considerable period.
Phishing groups have also developed e-mails capable of evading
anti-spam systems by sending messages in the form of an image
rather than a text file.
Other organised groups are using malware to reprogram PCs to
redirect requests to visit legitimate banking sites to fake
websites hosted elsewhere.
And some sophisticated spam e-mails can direct customers to real
banking sites while e-mailing their data to a fake site.
"You do not know when you have been phished and it is becoming a
lot harder to detect," said Jevans.