(CNET)  -- At a hacker conference no one is safe.



Demographic of Defcon conference for hackers is older, wiser and employed.



When I first went to Defcon in 1995, the halls were mobbed with teenagers and attendees seemed more concerned with freeing Kevin Mitnick and seeing strippers than hacking each others' computers.



Jump forward to Defcon 17 this year, which was held over the weekend in Las Vegas, things certainly have changed. The attendees are older and wiser and employed, most of the feds aren't in stealth mode, and even the most savvy of hackers is justifiably paranoid.



"Welcome to the hacker world," said Defcon founder Jeff Moss.



The evolving demographic of Defcon attendees shows that the hacker community, like all of us, is aging. But it's also a reflection of how the threat landscape has changed. Web site defacements have given way to much more serious risks like financial fraud and unaddressed critical infrastructure weaknesses.



It's a cornucopia of phishing e-mails, cross-site scripting attacks that poke holes in trusted Web sites, and criminals harvesting credit card numbers and selling them on the underground equivalent of eBay with guarantees of service and support.



Defcon and Black Hat, the pricier and more corporate sister confab held the two days preceding Defcon ($120 for Defcon registration versus $1,395 to $2,095 for phased registration at Black Hat), offer a forum for researchers to share information about vulnerabilities they find in software, hardware and systems.



Targeted this year were everything from the iPhone and surveillance video feeds to e-parking meters and security underlying the Domain Name System.



Vendors and users weren't the only ones who need worry. Attendees had plenty to fear and security experts themselves weren't spared.



On July 27, Web sites belonging to a handful of security researchers and groups were hacked and passwords, private e-mails, IM chats, and potentially sensitive documents were exposed on the vandalized site of security golden boy Dan Kaminsky. (Mitnick, whose jailing in the '90s for computer crimes made him a cause celebre at "Free Kevin" benefits at Defcon at the time, was among those attacked.)



There were more widespread threats at the shows, too. Anyone using the Wi-Fi networks at the events had better be careful lest they get their password sniffed and posted on the Wall of Sheep. Then there was the USB thumb drive that was passed around among attendees of Black Hat that was found to be infected with the Conficker virus.



Reporters who aren't nearly as geeky as the sources they interview are always easy prey. One reporter was concerned about being hacked via the local area network in the press room after a rare Blue Screen of Death crashed his laptop.



Last year, three French men were expelled for sniffing the press room LAN at Black Hat. They said they had obtained eWeek's and CNET's passwords but failed to prove the CNET allegation.



This year, three South Koreans registered as press were ejected for asking questions that led organizers to believe were on an intelligence-gathering mission instead of merely reporting, according to the IDG News Service.



I had a panic of my own at Defcon this year. I was connected to the Internet using an EVDO wireless card and a virtual private network and was startled a short while later when a Web page opened up out of the blue and I noticed the VPN was disconnected. Granted it looked like a legitimate page for my wireless carrier, but not wanting to take any chances I immediately logged off.



(See "Defcon: What to leave at home and other do's and don'ts" for tips on how to best protect yourself.) Unfortunately, I had neglected to disable the Wi-Fi on the laptop.



Because Windows XP event logging is lacking, it's not clear whether someone may have spoofed the name of a wireless network the laptop is configured to automatically connect to. Time to call the help desk.



At least I didn't use any automatic teller machines at the hotel. Defcon organizers confirmed on Monday that a fake ATM was discovered
What was passed around at conference? What was passed around at the conference? What do you share on Defcon?
USB thumb drive USB thumb drive information about vulnerabilities
question: What was passed around at conference?, answer: USB thumb drive | question: What was passed around at the conference?, answer: USB thumb drive | question: What do you share on Defcon?, answer: information about vulnerabilities