Worms are spreading faster and causing more damage than ever before, with blended threats increasing 20 per cent in the first half of 2003, according to the latest Internet Security Threat Report from Symantec.
By using combinations of malicious code, blended threats are creating greater damage to systems worldwide and have taken an even more sinister turn with the capability to steal confidential data.
The six-monthly threat report, which uses more than 20,000 sensors to monitor network activity in more than 180 countries, identifies virus trends, potential threats and the source of attacks.
Symantec Australia managing director, John Donovan, said the time between a security flaw being identified and a worm exploiting the flaw had dropped from months to weeks.
For example, he said Blaster used a well-known Microsoft flaw that was announced only 26 days before Blaster was released.
"This fact supports our analysis that the time from discovery to outbreak has shortened greatly,” Donovan said. “Of all new attacks observed, 64 per cent targeted vulnerabilities less than one year old."
Data theft is also on the rise via malicious code such as Bugbear and its variant Bugbear.B, discovered in June 2003. Once systems are infected, confidential data such as file names, processes, user names, and keystrokes is extracted, potentially compromising passwords and decryption keys.
Moreover, the creator of Bugbear specifically targeted banks, including Australia's top five, which were all included in the code.
"During the first-half of 2003, Symantec saw a 50 per cent increase in the theft of confidential data using backdoors," Donovan said.
"Companies need to implement controls that make it difficult for attackers such as updated firewalls, patch management policies and intrusion detection."
When a system had been compromised, attackers could install malicious code known as a "bot" that allowed the attacker to use the system for future scanning or as a launching point for other attacks.
The attacker could maintain a running list of the entire botnet by simply issuing commands through an Internet Relay Channel.