I wrote an article for CSO Online titled Computer Incident Detection, Response, and Forensics. It's online now, and it should appear in the next print edition as well. From the beginning of the article:
2008 is a special year for the digital security community. Twenty years have passed since the Morris Worm brought computer security to the attention of the wider public, followed by the formation of the Computer Emergency Team/Coordination Center (CERT/CC) to help organizations detect, prevent and respond to security incidents. Ten years have passed since members of the L0pht security research group told Congress they could disable the Internet in 30 minutes. Five years have passed since the SQL Slammer worm, which was the high point of automated, mindless malware. The Internet, and digital security, have certainly changed during this period.
The only constant, however, is exploitation. For the last twenty years intruders have made unauthorized access to corporate, educational, government, and military systems a routine occurrence. During the last ten years structured threats have shifted their focus from targets of opportunity (any exposed and/or vulnerable asset) to targets of interest (specific high-value assets). The last five years have shown that no one is safe, with attackers exploiting client-side vulnerabilities to construct massive botnets while pillaging servers via business logic flaws.
Read more here.