BEIJING - It was Chinese New Year Day (Jan. 31) in Shanghai and the much of the city had emptied out for the week-long holidays, including most of the construction workers and security guards at the unfinished 2,100-foot-tall Shanghai Tower.

Just after midnight, two daredevil friends, Vadim Makhorov, 24, from Russia and Vitaliy Raskalov, 21, from Ukraine, snuck past the remaining guards. Their goal: to climb the world's second-tallest building and record the experience for everyone to see.

Armed with GoPros and DSLR cameras, and evading security, the pair scaled all the way to the top of tower, even climbing higher, to the end of a construction crane.

This week, they released a thrilling, vertigo-inducing video that is quickly going viral.

"I've been on a lot of roofs," Rasklalov told ABC News from Bangkok. "But this was the most beautiful. When I saw just the two other buildings sticking up from the clouds, it was like flying in a plane. It was [expletive] awesome!"

Raskalov and Makhorov are at the forefront of an increasing popular craze among Russian youths called "skywalking," or "roofing."

Watch ABC News Moscow correspondent Kirit Radia's 2012 report on skywalking here.

Raskalov had no climbing experience prior to taking up skywalking four years ago. He had recently purchased the camera and realized he loved taking photos from dizzying heights. The climbing came naturally to him.

"I find it easy," Raskalov told ABC News. "I'm not fat."

The duo has taken skywalking beyond Russian borders. Last year, they caught controversy after they infamously scaled the Giza Pyramids in Egypt. As a result, Raskalov has found himself banned from going back to Egypt, Belarus and even Russia, which is why he now splits his time in Hong Kong and Bangkok.

The pair knew they were risking the wrath of Chinese authorities with the Shanghai climb but were willing to take the risk. They purposely picked the Chinese New Year season because many of the migrant workers leave the city to visit families at home. They arrived three days in advance and canvassed the site for security cameras.

Raskalov said that the hardest part of any climb is not the physical exertion or defying the fear of falling, but avoiding capture.

For that reason, climbing the almost-empty construction site of the Shanghai Tower was a piece of cake to them. The whole experience took 18 hours, mainly because they spent much of it hiding.

Their most difficult climb: the spire on top of the main building of the Moscow State University.

"Too many cameras. Too many guards," said Raskalov.

It took the duo five attempts before they made it.

Raskalov's goal is to see the rest of the world from great heights. On his immediate checklist: Seoul, Japan, North Korea ("easier for a Ukrainian") and the United States.

"I would love to climb the Golden Gate Bridge."

See more of Raskalov's photos here.