The future of malware: Trojan horses

Some of the most dangerous cyberattacks are the least visible ones.

Widespread worms, viruses or Trojan horses spammed to millions of mailboxes are typically not a grave concern anymore, security experts said at the Virus Bulletin conference in Canada last week. Instead, especially for organisations, targeted Trojan horses have become the nightmare scenario, they said.

"Targeted Trojan horses are still a tiny amount of the overall threat landscape, but it is what the top corporations worry about most," said Vincent Weafer, a senior director at Symantec Security Response. "This is what they stay up at night worried about."

The stealthy attacks install keystroke-logging or screen-scraping software, and they are used for industrial espionage and other financially motivated crimes, experts said.