For a second year, participating hackers took part in a social-engineering, capture-the-flag event this summer's at Defcon 19 security conference. And a newly-released summary of findings from the exercise reveal organizations are highly vulnerable to social engineering.\n\nThe exercise, called "The Schmooze Strikes Back," was organized by professional social engineer Christopher Hadnagy, author of Social Engineering: The Art of Human Hacking and founder of the web site social-engineering.org. Hadnagy released a report on the results this week, which can be read on his web site.\n\n[Also see: Social engineering: My career as a professional bank robber]\n\n"The event built on the first year's success by expanding the number of companies we called, the requirements for contestants and the flags that were sought after," said Hadnagy. "Some of the things that just made us drop our jaw were the amount of information that is leaked all over the web; open FTPs, documents marked "CONFIDENTIAL," vendors leaking information, and much more.'\n\nHadnagy said contestants only saw a small amount of resistance and virtually no company shut the participants down in their efforts to collect sensitive information that could potentially be used against them in a future attack.\n\nIn all, 14 companies were contacted by participants They included Apple, AT&T, Conagra Foods, Dell, Delta Airlines, IBM, McDonalds, Oracle, Symantec, Sysco Foods, Target, United Airlines, Verizon and Walmart. There were 62 potential "flags," or pieces of sensitive information, to capture and 14 were successfully captured over two days.\n\n [Find out how social engineers pull it off in 5 more dirty tricks: Social engineers latest pick up lines]\n\nContestants conducted online research on targets and contacted them using "pretext" scenarios; pretending to be customers, employees or sales representatives from another organization. Only four companies gave participants any resistance, said Hadnagy. The companies that callers had the most difficulty extracting data from were retail-based companies, he said. Companies like AT&T Stores, Walmart, and those which dealt with customers in retail settings were more cautious and reluctant to answer questions and inquires. \n\nHowever, companies with large call centers or customer support representatives, such as those in the airline and tech industries, were the weakest, said Hadnagy.\n\n"AT&T took the cake as being the most secure out of all with the highest rank and Oracle scored the lowest," said Hadnagy. "It seems that social engineering penetration testing is more needed than ever, but still one of the least sought after services. Reading results like this makes me wonder when corporate America will wake up and realize that without spending the time and money to test and educate, this problem will never get even a fraction better."