'Zero Days' Last Up to Six Months for Some Malware

From CIO:

'Zero Days' Last Up to Six Months for Some Malware

The majority of new malware is added to antivirus signature databases within 24 hours of first appearance, and 93 percent is detected within a month, but it can take as long as six months for antivirus to catch the remaining 7 percent, according to a new study by Atlanta-based security vendor Damballa, Inc.