Blended threats, which combine malicious code with vulnerabilities to launch an attack, accounted for 60 percent of malicious code submissions in the first half of 2003, according to Symantec's Internet Security Threat Report. The number of blended threats increased by 20 percent. Microsoft's IIS Web server is a prime target for blended threats, because it has been highly susceptible to them in the past, the report says.
Submissions of malicious code with backdoors -- which often are used to steal confidential data -- rose nearly 50 percent, from 11 in 2002 to 17 in 2003.
Symantec documented 1,432 new security vulnerabilities during the first six months of 2003, a 12 percent increase over the same period in 2002. Additionally, 64 percent of new attacks targeted vulnerabilities less than one year old. Indeed, the report indicates that the time from discovery of a vulnerability to an outbreak continues to shorten significantly.